Being married to someone with a different cultural background didn't even come up as an issue when DH and I decided to get hitched. There were those around us who thought it may cause problems but in nearly five years there haven't been any hurdles that we've encountered culturally.
After getting married we met quite a few couple who chose partners outside of their culture as well proving to me that we are just becoming a huge melting pot here in America.
I just received this link and thought that you'd also enjoy seeing how we are all becoming just plain 'ole people. . .