The Supra
I'm sure that Toyota will bring the moniker back, probably around 2005-2006. They will do exactly what they did last time. The Z32 came out in 1990 and then in 1994 (1993.5) the MK4 was released. They took everything the Z32 had done and made it just a little faster, little wider, and a little more expensive.
As far as the power plant, I seriously doubt it will be an I6 much less a turbo. Its just not the trend any more. The 350Z is NA, the RX8 is NA, and the damn EVO will be NA next year from what I have read. The only way I see Toyota making a turbo setup is if they want to compete with the 2005 G35 GTR (Skyline)..so who knows.
They cant afford to price them selves out of the market the way they did in the mid 90's...bottom line.
It will be interesting to see what they do.