Zloth
I smell a... wumpus!?
Enter Gaikai. You don't play the game on the PS4, you play it on Gaikai's servers. If PS3 users are lucky, the PS4 will be able to tell Gaikai what PS3 game is in the disk drive so they can play it for free while the disk stays in the drive. (At least that's what I'm guessing.) They could probably stick PS1 and 2 games up there, too.But how could it be backward compatible? The PS3 is based on completely different technology. Both consoles have pretty much nothing in common except for the name.
It will take some dealmaking with the publishers but I think a publisher would rather get a few sales via Gaikai than see their PS3 game sales go to 0 as the console vanishes. If the current game owners get to play free then they would only be getting money from people who see their friends playing a PS3 game on it and buy a copy themselves so I wouldn't bet on numbers much larger than 0.
In other PS4 news…
The network is going to use real names. I guess they didn't learn from that whole MMO stink (in WoW?) a year or two back.
There's one very interesting social feature: calling for help from your friends. In fact, you can even hand over control to a friend to get you through some tricky part of the game (or show you how to do something or whatever). I can't figure out if I like this feature or loathe it but it's definitely interesting. Naturally, *I* would never need to use this feature but perhaps there are some damsels in distress out there….
All in all, I'm really looking forward to the boost these things will give to gaming. Lots more tesselation and physics! A pity its Havok instead of NVIDIA but oh well…