Besides native games & ports there are all kind of emulators. There is even an implementation of the Windows API (WINE) which allows one to play Windows games with variated success.
However, one might want to run a specific game on Linux.
The focus on the NIT is to get all kind of classic games (and emulators) running. This opens up possibility to get a huge arsenal of games working on the NIT however mostly 'old' games or clones of old games. Useful for several reasons e.g. nostalgia but also if the game formula is well or aspects of the game are good (e.g. storyline in Beneath A Steel Sky) it is potentially a lot of fun.
WINE's rendered completely irrelevant for the tablets, of course, but we've got a good assortment; FPSes and racing games, as mentioned above. Including (sort of in the racing genre) Tuxracer/planetpenguinracer/whatever it's called these days.
But also Chromium B.S.U; though I'm not entirely sure how it'll work with a touchscreen, it should be doable. (It needs to look for some key, rather than the mouse button.) If you haven't played that, then you don't know what you're missing. Not to demean Tyrian, which we already have, but they're different, and you need both.
I'd mainly be interested in Chromium and Q2/3, which are somewhat wanting in impressiveness these days, as they already run on "everything", but are good solid fun (which is what I want from a game).
That's a nice wish, but there are several ways of getting "3G access", and they've all been discussed at length.
Right now, all NITs can get 3G access by pairing with a 3G phone over BT, and using DUN or PAN.
Other options include building a 3G radio into the tablet; this is bad because it ties the tablet to one particular technology, and likely to one or two frequency bands. Also, those without 3G service must pay for extra hardware they'll never use; while the price increase may be worth it for some, it'll probably stop some people from purchasing it.
The best option that I can see is to have some sort of slot, probably under the battery door, which would accommodate various 3G radios; this would cost substantially less than an integrated radio, would afford flexibility in network technology, and could be used for purposes other than a radio as well. The size tradeoff is still made, though, even for those not using a radio/storage/whatever card at all.
But BT's not bad at all, if a slot doesn't happen.