I think this would be interesting if they could get it to work on the scale needed to be profitable, but I don't see it happening.
I am guessing (and maybe incorrectly) that there are 2 kinds of Linux based web book users:
1) the proto typical techie who likes the freedom of configuration choices that it gives you or
2) the person who got it because it was cheaper or didn't know the difference and doesn't care, as long as they can get email and surf the web (and use their web based apps).
The evil capitalist in me thinks this would be a great thing for the revenue stream, if you could lock them into using our store and only our store (contrary to the open source concept), but I don't see that happening.
I realize this is slightly off topic, but I find it ironic that the mobile phone platform that seems to be the most open to allowing you to write and install what ever program you want is windows mobile (yes, that is what I currently use). Everyone is talking about "The" apps store, but WM phones don't have 1... they have an untold number of sites to get apps from, several dedicated to free (of cost anyway) sites, but this fact seems to be left out of the Iphone/Pre/Android discussions by various tech sites.
back on the original topic, I wish them all the luck, as it is nice to get compensated for your work, but I don't know if there is enough commonality to get enough return on investment for the vendor on setting up an app store. If this can be achieved, then it would pave the way for the developers to benefit as well.