The SNES versions were great. The last NBA Jam game I remember was that notoriously shit GBA effort that got 6% from Hyper (at least Superman N64 got 10%).
I can imagine a whole heap of licensing hassles that completely stuff our chances of ever seeing the original NBA Jam on any of the console download services (it certainly didn't make it into Midway Arcade Treasures).
God, I hope they nail this Wii effort.