Lol, How could Mickey travel to the past? He has a portal underneath his castle that goes back to the old b&w days. Come on now XD
We all know about previous keyblade masters/wielders from what Xigbar said in KH2. Events are probably repeating themselves (maybe something like the Matrix, except not really in a loop) and Mickey has been trying to figure out what's really going on. His findings could be what the letter at the end of KH2 was about. I think we'd have to deal with the realm of darkness a little bit in one of these games.
How the heck would CoM 2 work? I mean the first one was between I and II, so CoM 2 could be the bridge between II and III, with the PSP KH game being events that took place before KH I started. I guess that makes sense... I'm imagining one of those two will feature Roxas... maybe both. Sora would have his grand return in KH3. These two games are probably just set up for the finale on the PS3 version... if this is all true >.>