No, the prodigious Romney spawn are not running for office. Romney himself is thinking about getting back in!
As hilarious as that would be (I miss the good old days, when the Republican race was completely FUBAR), it wouldn't do Romney much good. According to the AP's delegate count, Romney's former victories gave him just two more delegates than Mike Huckabee currently has. It's commonly acknowledged that it is mathematically impossible for Huckabee to win the nomination. The same goes for Romney.
Mitt, listen. To paraphrase Jay-Z, you got money stacks bigger than John McCain. Enjoy your retirement. Or, make like John Edwards after 2004 and start campaigning in Iowa now.
Update: Josh Romney proves me wrong! He is considering running for Congress!