My prediction for the PSP2 is this:
It will support up to 720p resolution and be able to be plugged into your PS3 to view it on the TV (and when paired be able to use your PS3 controller for its games).
Games will come on special hardmodded sony memory sticks (with say built in memory around 128gig) and it will support BC with the PSP only via the PSN.
It will support PS2 games downloaded off the PSN (of course having dual analog sticks)
The PS2 games seems like it will work. Im thinking the psp and ps2 will be discontinued around the same time and that day they will add PS2 BC to all ps3s via a firmware update. Then shortly after they will start offering ps2 games off the PSN to use on your newly bc ps3 (and the future psp2)
As far as PS4:
Will come standard with 3D gaming (but still use the other if you cannot support 3D gaming)
Will come in at or around end of 2013
(This way there will be plenty of 3D televisions out on the market (and they will be cheaper)
Will support 500gig multilayered Blue-ray discs (I think its Panasonic who is doing these now?)
Will support 100% BC with ps1/ps2 games
(I dont think Sony will do BC with the ps3 unless the hardware in the machine is very similar)
Essay Pro