Since there's probably a heavy compression used and the modifications happen all over the wikipedia, I don't think there is a way. The only thing they could probably do is to split the articles in several categories and allow to update them separately.
It's nice. But just wikipedia doesn't sound GREAT. Maybe project Gutenberg stuff will be a good addition. I believe that the device has space to grow in.
No WikiMedia images? That’s a shame. I guess that including images for every article would suck up a lot of space and wouldn’t work well on an eInk black and white display anyway, but a lot of the more useful information on Wikipedia is presented in chart and graph format.