I don't think it's a good idea.

Would be EPIC

they can do co op and split screen both.

or go for LBP cooperative to move forward way.

from what i see nsmb wii it's more about playing together, rather than cooperate.

SMG2 will be a lazy copy of SMG

That said I'm still looking forward to it because the first one was epic.

it would be great to have online multiplayer with wiispeak support but I have serious doubt about this.

No. It has Yoshi in it.

It would be great, but i wouldn't hold my breath.

Expect reviewers to lower Galaxy 2's score for not including multiplayer, because they'll see that as standard after NSMBWii.

Possible, however it will likely implement co-op as it did in the origional. Sure it won't have a split screen co-op mode (likely) but their is a strong chance that their will be a similiar to the origional.

I dont think, it would be much harder than NSMB Wii. Unic way is slit screen but I wont look good, I prefer a single player, maybe with some extras multiplayer minigames would be good =)