The official 2012 rules are available here. The organizers may adjust some of the experimental aspects of this year’s competition.
The 2012 CFP is also available, but the official rules PDF above is the authoritative source, and takes precedence should there be a discrepancy.
Submission this year will be through the SMT-Exec service, an execution service for SMT solvers. You are encouraged to upload early and often to test your solver on the competition infrastructure. SMT-Exec allows you to keep such submissions private, and when you have completed your competition solver, you can upload the final version of your solver for competition, or mark one of your previous uploads as your competition submission.