If you can make it more powerful and still as simple to use as ExtJS grid, I'd consider paying, but only if the cells could use the same kind of fantastic templating and CSS options that you can in ExtJS.
As an Ubuntu One user, there's only one platform I would use Ubuntu One on instead of Dropbox: Ubuntu. The only reason I use Ubuntu One instead of Dropbox on Ubuntu is that I can sync any set of folders or files. I hate having everything stuck in a Dropbox folder.
Actually, many people do daily or semi-daily commutes already. I commute and sometimes it's hard to find seats when taking the Acela Express between New York and Boston.
At this point I think the problem is price. You only see white collar workers on the express because a round trip is $200+. If any of these people (myself included) had to foot the bill for the train tickets I doubt the trains would be nearly as full as they are.
My Vaio TZ has all those things working out of the box with Ubuntu 10.04 LTS, along with microphone and camera, memory card readers, and Sprint EVDO card.
I agree with you that getting Linux to work on laptops can often be frustrating, but if you check compatibility prior to purchase (Ubuntu forums are great for this), then you'll get a good idea of what to expect before you buy.
That's simply not true. In my high school, for example, Napster got installed on all computers in the computer lab and a full class was dedicated to teaching everyone how to use it. For reference, another full class was dedicated to learning how to use "Search Engines". Frankly, I did not know a single person under the age of 30 who did not have a massive collection of MP3s and divx movies by the time iTunes came out.
Those "People" would actually be called teenagers, and I never met one who didn't know how to use Napster or Kazaa back when I was one of them.