I don't know what "Hulu app" you're referring to, but Hulu isn't going to all of a sudden just find one box it likes. I read an interview recently that Hulu totally believes in staying on PCs and off TVs. Considering the obvious deal that it's owned by TV companies, duh. That's why they killed the plug-in for the ATV.
I downloaded Hulu Desktop, and it's very neat. But it's for computers. Yes, you can hook a computer up to a television, but that's different for most people from a box made for TV -- Blu-ray player, satellite/cable box, Apple TV, game system.
The same article said as people do things like use Mac Minis for media centers, entities like Hulu will have to cave and get onto TVs. But don't expect some magic portal. Hulu still doesn't make a fraction of the revenue that TV ads do for the shows. It's the same deal for us with Web ads versus newspaper print ads. Nobody has figured that deal out, and nobody has figured out how to make good money with ad-based streaming.
One last thing about the Xbox 360: Check out its power usage. That and the PS3 suck long and hard when it comes to power consumption. I think they pull double the wattage of an average computer. I'm a green nerd, so I'll stick with my MBP and my power-sipping Blu-ray player. Now if someone will give me $3,000, I'll go buy an LED TV.