So Sony is competing against itself.... This is one area where I think it's a bad idea and Sony will need to tread very carefully.
So for a window of time Sony will have 3 home consoles it is trying to support, none of them compatible with each other.
Yikes that's a lot of hardware to support, things like this make me worry for the future.
No, they're not.
As Foxi mentioned, the Vita is an entirely different subset from the PS3 or similar consoles. It's competing in the entry level console market (meaning like the Ouya) which is just starting to emerge.
My point is that, priced lower than the PS3, it will grab the attention of entry level consumers who wouldn't really go after a PS3 immediately. It doesn't fill the spot of a PS3 or PS4 either.