If Porsche gets involved in GP's you can bet they'll be buliding engines. before they ever get involved with a whole bike.
I think the 800cc rule will be like the 990. Good because it will encourage more manufacturers, bad because it'll hit the privateers hard. Some currently good bikes will go bad (Like Suzuki did), and some new manufacturers will emegre with potential (Like Ducati did) Some will keep on top, as if thyre never gonnd go down (Like Honda) and some will dissapoint us (Like Kawasaki). It'll be good for variation, but I'm thinking it'll be bad for satellite teams.