Gameindustry.biz points to a PDF found on Sony's developer website that answers a ton of questions about their upcoming Home service.
Highlights include -- launch roll out date (October 2007); the size of the initial download (500 megs); friend limit cap (50); and the ability for retailers to have their own Home spaces. Can't wait for the EB Games space. "I see you've earned all of the trophies for Ratchet and Clank Future: Tools of Destruction ... did you know that game can get you $30 in trade-in credit?!? Would you like to reserve Resistance 2 or Madden 2009?"
If you have time to kill, read the entire PDF -- it answers a lot of questions you might already have and are too afraid to ask. Like the all important "What moderation is used in the system for vulgar / abusive language?"