No, apparently Warner Brothers have confirmed that Smallville will continue for at least one more season after this one. As for crossing over with Superman Returns, don't worry, they are different interpretations of the same character. As such they do not occupy the same continuty/timeline, SR has the first two Chris Reeve movies as a "vauge history" according to director Bryan Singer.
A 'vague history' is a period of time that has gone before, in which things aren't really that clear I guess.
I think what Singer means is that 'Superman Returns' is based some years after the events that happened in the first two Superman films. As such, no General Zod (boooo!) but Lex Luthor is obviuosly free from prison after serving his term, or has escaped from another maximum security jail. The basic premise I think is that Lois Lane has gotten on with her life (unfortunately that damn 'memory kiss' from Superman II, why oh why Richard Lester ever put that in) and the story is how Clark/Superman and Lois get on from this point.
"One must be a fox in order to recognize traps, and a lion to frighten off wolves."
