With the announcement of the iPad yesterday, everyone and their uncle has their take on who will want to use it, who won't, and exactly what niche it will fill in the computing ecosystem. So of course, I can't help but put in my two cents as well. :)What is the iPad?One of the main points of contention seems to be how to categorize the iPad. What is it, really? Is it just a big iPod Touch? Is it a type of personal computer, just a variation on the laptop form factor? Or is it something entirely new that doesn't fit any existing category?To start off with, at least in its current form, I definitely don't think you can call it a personal computer. The main reason for this is that, while it has a lot of functionality that a PC (or Mac) has, you still need to have a PC in order to be able to use the iPad for most of the things it does. The primary way of getting content onto the iPad is by syncing it with your desktop or laptop machine, via iTunes. Without a PC to attach it to, you can't put any of your music, photos, or videos onto it, and you can't even update the software on it or back up your data. In order for the iPad to replace a PC, it has to be able to exist without requiring another PC. Could this happen in the future? Perhaps, but it's definitely not the case right now. For now, the iPad is a secondary device, and will almost never be somebody's sole computing device. (One exception to this would be a family that all shared a single PC, with each member of the family having their own iPad. You still need a PC, just not one per person )In his presentation, Jobs did specifically pitch the iPad as bridging the gap between PCs and mobile devices such as phones and music players. Currently, the most common tool for this job is the netbook, which is basically a small, low powered, inexpensive laptop computer. The problem is, while a netbook is certainly more portable than a full sized laptop, it still comes with all the complexities and headaches of a full-fledged PC, such as figuring out how to install new applications, dealing with viruses, organizing your files on your hard drive, and so forth. The basic premise of the iPad is that personal computers, no matter their size, are not the right tool for the large number of users who just want to do fairly basic tasks with their machines, such as browse the web, do e-mail, listen to music, and view their photos. The iPad is designed from the ground up to fill that gap.Further proof that Apple is moving aggressively to capture this market can be seen in their pricing. $499 is a very competitive price point, especially for Apple. Remember, this is the company that started out charging $400 for a music player and $500 for a cell phone. :) It's not quite at the $300 price point most netbooks are priced at, but I think it's close enough, especially given the difference in quality between the iPad and a netbook. I predict that people will buy tons of these things at $499, then next year Apple will drop the price a hundred bucks or so, and then they'll sell even more, just like they did with the iPod and the iPhone.Open vs. closed platformsOne concern that many people (especially developers) have is the closed nature of the iPhone/iPad, both in terms of media content and software. It's become pretty clear that Apple wants to have as much control as possible over the user experience on these devices. They act as sole arbiter of what software can and cannot be run on the device. If you want to write and sell software for the iPad or iPhone, you have to go through Apple. The downsides to this have been pretty well hashed over, and include arbitrary limitations on what is possible for your software to do, risk of rejection due to some reason not explicity stated in the SDK agreement, risk of rejection due to a simple error on Apple's part, and the ability for Apple to stifle competition to their own apps.What I think makes developers even more nervous though is not necessarily the current state of things, but rather the trend of where Apple appears to be headed. The iPhone has been a monster success, and presumably Apple will see at least some success with the iPad as well. As these platforms comprise more and more of Apple's business, Apple could someday decide that they want to apply the same level of control to software written for the Mac, which does not currently have the kinds of restrictions that the iPhone OS platform has. For programmers such as myself who make their living on the Mac, the though of ceding that much control of my well being to Apple is certainly a scary thought.Realistically speaking though, I personally don't see this happening anytime in the near future. The primary (though not sole) reason for this is the huge difference in market share that Apple has in the smartphone and music player markets versus their share of the PC market. When it comes to phones, the iPhone is currently the 800 lb gorilla, and all the other phone companies are scrambling to retain their marketshare which is steadily being eroded by the iPhone. In the PC market though, even with the recent gains the Mac has made, Apple's marketshare is still pretty low, much much lower than the iPhone.Right now, for smartphone development, the iPhone is king, and everyone wants to develop for it, because that's where the largest number of potential customers lie. This being the case, most developers are willing to concede to Apple's terms in order to be able to sell their software to millions of iPhone users, and don't have a lot of other viable options (though hopefully Android or some other platform will become good enough to compete well with the iPhone).On the Mac, however, if Apple were to announce that all Mac applications needed to be approved by Apple in order to be sold, you would no doubt see developers desert the platform in droves. While developing for the Mac is nice, there are very viable alternatives for Mac developers when push comes to shove, including developing using .Net, Java, or any number of web based technologies. Simply put, Apple just doesn't have the same leverage on the Mac platform the way that they do on the iPhone platform.Do you need dedicated linux servers?I also don't give much credence to the theory that the desktop computer will eventually just go away entirely, meaning the Mac platform will be gone, and the iPhone/iPad platform will be all that's left. I think the desktop will always be an the forefront of computing, and while mobile devices such as the iPhone or the iPad may take the place of some of what people formerly used laptops for, people will always want to be able to leverage the full power and flexibility that a true personal computing platform provides.So basically, while I think it's good to be wary about the openness of the Mac platform in the future, I don't think this is something to worry about as long as the Mac's market share stays relatively low. Apple currently only aims for the high end market, opting to make money off of high profit margins on fewer machines rather than selling more machines for less money per unit. Unless Apple changes this strategy drastically, I don't see the Mac's markeshare growing by leaps and bounds, certainly not enough to be anywhere comparable to Windows' share of the PC market, or even iPhone's share of the smartphone market.