I bet Smash Bros. will be released on the same week of Brawl.
And I wonder why Super Mario Kart hasn't been added yet.
They are already doing similar things like that..
When
Super Paper Mario came out,
Paper Mario 64 was put on the VC. When
Mario Galaxy came out,
SMB3 was also put on the VC. The VC games were added the week before the release date of the current game, I believe..
I'm going to assume that they are going to wait and put
Smash Bros and
SMK on the VC when their respective Wii game comes out. That's just me making up theories, though..