This has been a common question the last couple of days with Hanna and Ike out there. No two hurricanes can form together into one mega storm. The laws of physics just will not allow it to happen. What is more likely to happen is for the two storms to spin around each other and one will either die off and the other may get stronger or die off as well. This is called the Fujiwhara effect, named after a Japanese meteorologist who first explained the phenomenon. It would be interesting to see though. The strong winds around tropical systems would normally keep any other storm at bay or possibly cause it to weaken.

~Meteorologist Keith Monday~