What Marcos said is right on par...except that the break-up was officially announced by Wind-Up on June 4th, 2004.
You can go into a little more depth about the break-up, though, by reading some interviews done with Stapp and the rest of the members of Creed.
www.passionbreedsfollowers.com is a great Stapp fan site that has links to the interviews he's done since the break-up. As for the interviews with the rest of the guys, you can probably find all the links in various threads in the Alter Bridge forum on here or by going to an Alter Bridge fan site like
www.alterbridgeband.net.
Stapp's solo CD is scheduled for release November 22nd, 2005. The first single, "The Great Divide", is scheduled for release on Rock radio September 25th, 2005, I think. You can find more info on the solo stuff either in the Stapp forum here or by going to PBF.