Hmm...well, metasploit has a db_export function that will let you get data out & import it elsewhere. To do it automatically, I think you'd have to do some Ruby coding, and maybe some SQL stuff, too. Have a look at the db_export code; that might get you on the right track. I also suggest posting this question on the metasploit mailing list, and see what the folks there say.


I've seen instances of appending to existing records, and new entries in others, when running the output from multiple tools into MSF. I usually store test results in dradis. But don't take my word for it, do some testing & see what you get.
