Hulu has it blocked. Just like HBO, and some other apps. It's up to the content provider if they want you to output it or not.
It's super lame, and what not, and (considering you have to PAY for Hulu Plus) stupid as hell. Though, I personally blame the studio's as I'm sure they're the reason why this crap goes on. Same reason why there are certain shows you HAVE TO WATCH on computer, and can't on the Hulu Plus apps. Again, completely stupid considering you're PAYING them for the Plus stuff.
Also, yeah, you get commercials. Some shows, and the movies don't have them, but they're still there.