My 2 cents...
There will be a big place for desktop puters & mice for a long time to come. Personally, Touch may be nice or neat but, I'm quite w/out it; although there is a place for it in some devices but not sitting @ my desk poking @ my 24", thanks. But, in many environments, from domestic to Education, business, science, powerful, robust, capable desktops will have a major place. Yes, A goal of Win8 is that it can play on all platforms. The whole Start conversation, frankly, eludes me... discovering a few 'tricks', customizing & personalizing investigating & learning, I'm fine w/ Win8; it's, certainly, a wee bit different but, @ the end of the day just another version of a computer OS. But, I'm 'old school' & maybe that's the explanation... I live on a desktop, I travel from there, I work there, I work & move from there & back, again. I don't get APPs. Fun & cute, sure but, why? I find I keep asking myself, why? Aside from them not seeming (YET, I guess) to be finished, complete, refined, blah, blah, blah... but, why? I can't seem to get past finding nothing I could do, see or find, all along and still can. Weather, videos, photos, E-mail, games, music, ad infinitum... never needed an 'APP' for any of it and still don't. Sure had always heard & known of 'APPs' for phones & stuff, all of which, stuck me as 'novelty' items, bells-n-whistles for trendy folks, niche markets & kids. For me, on my desktop, they strike me as unnecessary, redundant, a useless distraction & leave me asking, why?
Drew
PS: Might be somewhat rhetorical...