I'm all for it. Give me choice. Lower prices at day and date would be nice, but I'll also take cheaper, older games. Having Mass Effect or Crackdown at a $20 download is good stuff. I've also become really attached to playing XBLA and PSN games by just selecting from a menu. I love it. If I can get reasonably priced DLs for games I know I'd keep and play for a long time anyway, then cool.
I'm too lazy to check out that HDD install thread -- about how big are 360 games? I seem to recall in that thread that games are about 4 to 6 GBs on average. I think even the 60 GB HDDs would be tight if you were serious about XBLA, XBO and full 360 games.