Hi just heard about lbp3 and wondered if it will be cross compatible with lbp psvita?
also will the costumes that have been paid for in current versions of lbp be available in lbp3 with out having to repay for them?

Oh erm i would love kingdom hearts, doctor who, star wars and star trek costumes either on lbp3 or psvita.

while your here reading this try out my level too: http://vita.lbp.me/v/jcxg6/

LBPVita costumes will most likely be usable. Including DLCs (Like in LBP2). But its not proven.
But levels will probably not.

Yes and No

Considering that PS4 and PSvita are linked consoles it will.

If you have a PS4 then Yes
If you have a PSvita then No

Hope this helped

~ Mr lasanga