In my experience, ATOM chips are very bad when it comes to HD playaback. even with the Nv GPU i just don't see bluray playback being stable. how would you intend to watch bluray though? given it doesn't have a drive, you would need to convert the fiels anyway no? so just encode them into a more netbook friendly format.
If your intending to watch Blu ray, a netbook should not even be considered.
Netbooks are basically really big blackberrys, they are good for basic internet and nothing more.
not entirely true. one of my hobbies back when netbooks first came about was to get stuff running that should be impossible. i successfully got oblivion running on the original eeePC 701 at a fairly playable rate. people often under estimate netbooks. but your point is still valid, you do need to limit your expectations.