"Holidays 2013" so I'd say November.
No backwards compatibility. Not sure why people actually care about this feature. It's not like your old machine suddenly disappears if you buy a new one, and besides the PS2 no machine has ever really done backwards compatibility anyway. The 360 had limited compatibility that was gimped to say the least. I'd rather a machine with no backwards compatibility then gimp a new machine to make it work with old games.
In the plus side, PSN will be doing digital distribution of 'critically acclaimed' PS1, PS2 and PS3 games