I'm reading a lot of rumbling this morning from gamers about how MLB.tv isn't worth the money and "why would you pay to watch something that is free on TV?"  I understand that some may not think that this is all that exciting, but as a baseball fan -- and as a guy who cancelled cable over a year ago -- this is fantastic news.  Beyond the specifics, it's a sign that content like this is going to be not only delivered, but also developed for consoles and other "alternative" media solutions in the living room, i.e. Roku, Boxee, etc.   
 
Netflix has paved the way and I'm glad to see something like MLB follow.  It is odd that it's baseball, even with the strong built in audience with The Show, on account of the league being constantly and comically mismanaged in terms of media and how it presents itself to a wider demographic.

So far, I'd say yes.  I haven't received a game yet, but I've sent three off and I've been building up my points.  It's a nice alternative to selling your games at Gamestop, which I've done for years simply out of convenience.  I have friends who have done the Amazon trade-in program and have been very happy with that, but I still can't get past the mental barrier of only getting back a few dollars for games that aren't very old.  Again, I still haven't received a game yet, but that's my fault for having relatively new games on my request list.  Hopefully something gets shipped soon.