Most recent rumors I've heard in the last day or 2 are:
PS4 launching in November w/2 SKUs - $429 & $529
New Playstation Eye included w/all systems. (To go w/what seems to be Move functionality built into the prototype controller pics floating around the last week or 2)
Streaming of games planned. Gaikai has registered several web domains with name variations based on "playstation cloud"
Console can be controlled via smartphones/tablets.