Its pretty much all been posted but its spread out over a ton of threads, so I'll try to answer as much of them as I can.
1. PRIDE is going to remain in the ring.
2. I would assume it'll be decided ahead of time in the contractual negotiations. No real concrete news on this yet.
3. Fighters are going to remain in the org's their contracts are in. So UFC guys are UFC guys and PRIDE guys will remain PRIDE guys. The cross-promotion fights will probably just count as a fight on their existing contracts.
4. Dunno, but since both org's are remaining basically the same, I would assume they will use their own org's gloves.
5. I don't think they are planning on uniting the belts. Keeping the org's seperate yet trying to unify the belt would water down the losing champs division and organization. They may go the route of creating another belt, a Champion of Champions Belt or whatever.
6. Mirko vs Fedor 2, Chuck vs. Hendo, Shogun vs. Chuck, GSP vs Gomi, Gomi vs. Sherk, etc. There are way too many to list.