Have you ever given much thought as to whether an iPad could replace your laptop? Lately I have been. Maybe it's been the rumors of new MacBook Air's (MBA's) coming out which will really antiquate mine. Or maybe it's the promise of a brilliant looking touch screen (when will laptops also have touch screens?). The problem with an iPad and probably any mobile device (read Playbook, Kindle, etc.) is that most of them will be designed for consuming media and not creating media.
I guess it really all depends on the user but as it turns out I do quite a lot of consuming media (reading blog posts, news sources like the Wall Street Journal, Wired and HBR.org, etc.) and creating media (writing blog posts, writing a report for the occasional class, taking notes in OneNote, creating virtual environments, etc).
Most of the creating I do could easily be done via the web - except the major word processor companies don't allow editing through mobile browsers. Have you ever tried to log onto Google Docs or Windows Live Apps from an iPad or mobile phone? You can read but you can't write! Sure I could still blog through blogger.com but I wouldn't be able to upload new flickr pictures or test / create new virtual machines. It's not like I do that often but when I want to I want to now not later!
Maybe future tablets will fix this functionality gap or maybe Google and Microsoft will fix the problems themselves. I mean who wants to have to buy additional Apple word processing and spreadsheet apps when there are perfectly good versions online? In the meantime computer manufacturers have no reason to fear iPad's cannibalizing laptop sales - at least not from me!