It begs the question... What would be the point of having a ps4 and a ps plus subscription? There won't be any ps4 games to add to psplus since they will all be new games... And you won't be able to dowload or play any of the ps3 games in ps plus on your ps4 since its not backwards compatible...I guess it will be like vita where at first its not included in ps plus but eventually it will be. So like a year after launch maybe ps4 will be included in plus?
I suspect Gaikai streaming service will be tied in some way to PS+. Whether it would be tiered pricing is really the only question about it.
That being said, since the PS4 will have a limited library of games initially, I could see a $50/yr price tier, as it is now, that covers all three platforms (PS4, PS3, PSVita), which would add even more incentive to hold on to your PS3 after the purchase of a PS4. This tier would also include a shared cloud save service betwen the PS3 and PS4 and the current separate cloud save service for PS Vita.
I imagine that Gaikai will be added to a 'Premium' PS+ tier which would cost about $80/yr, which includes the current PS+ plan for all three consoles, plus unlimited Gaikai game streaming for the PS4 (and possibly PS Vita).
I recent found out Gaikai did not require a subscription fee before Sony acquired them but yeah, as you said, they will probably require a subscription fee to access games on there. I wonder about purchased games though. Streaming games is only an attractive alternative to traditional backwards compatibility only if it did not require a subscription fee to access otherwise, I think I would rather just play PS3 games on a PS3, even though it won't last forever...
I would be cool if Sony allowed us to access the games we buy for free and only charge a subscription fee to access the other features of Gaikai, similar to how Gaikai used to be.
Its not a stupid question at all. I wounder myself what will happen. I do like the plus but I wish they would cover all your accounts for one price. Gets to be a bit expensive to cover all your accounts. I hope sony will shed some light on your question soon. I am not sure what to do as far as buying new items on home and ps plus. But I dont think anyone can really answer you question yet.