Do I even need a tablet?

Apple are apparently going to announce their oft rumoured tablet computer (possibly called the iSlate) in the next few weeks and Microsoft unveiled their underwhelming (stock Windows 7 on a 5” screen, really?) new ‘slate’ PCs at CES earlier this month. This form factor has been tried before but hasn’t been a widespread success, they are often large and bulky with poor performance; this new generation promise to smaller, lighter and well, we’ll have to see about performance. But still who needs them? A pure touchscreen interface isn’t ideal for work, I can’t imagine coding or writing documents with an onscreen keyboard on a regular basis, more suitable, although still unpleasent to spend much time using, are the cheap netbooks that have become so popular. So whats left, web browsing and media playback? I already have a great product for that in the iPhone, a fair percentage of my personal web use is already done on my iPhone. Using excellent mobile formatted sites like BBC and Google’s web apps and apps like Facebook and Tweetie; I rarely miss a larger screen. About the only situation I could see the larger screen of a tablet being an advantage is as an ebook reader, however the larger the screen, the less likely I am to carry it, which is the strength of the iPhone I always have it to hand. But what will the iSlate be? It makes sense that it would run existing iPhone apps, however it’ll be a huge disappointment if it turns out just to be an iPod touch with a big screen, but equally I don’t want Apple to go the Microsoft route of cramming their full OS onto a small device. Having owned a few Windows Mobile devices and a touchscreen PC I know that using unmodified Windows on a touchscreen is awkward and I don’t see OSX being much different. Microsoft’s Courier concept that cropped up a few months ago looks great and I’d love to use something similar, could the iSlate offer this kind of functionality?
Having said all of that, the guys at Apple are smarter than me and its quite likely they’ve thought of something I haven’t and the iSlate will be the most desirable product of 2010. So I’m saving for one, reading all the rumours and patiently waiting on the live blogging of the announcement anyway.