I recently signed up. Mainly because I didn't want to spend $60 a game on new 360 games, and no place conveniant to me has a good selection to rent from yet. I signed up on Tuesday afternoon, had emails by Wednesday saying that the first two games in my list had shipped. Today I had them waiting for me in my mailbox when I got home.
Seems like an awesome, awesome concept, well executed. Shipping was quick, the packaging is simple, and the selection is broad.