I have to admit it feels a little strange to see romance go this direction. I have always associated steampunk with science fiction and, of course, fashion.
For reference here are some authors and titles that relate:
Gail Dayon's HEART'S BLOOD and NEW BLOOD
Katie MacAlister's STEAMED: A STEAMPUNK ROMANCE
Ginn Hale's WICKED GENTLEMEN
Meljean Brooke's THE IRON DUKE (also a relating prequel story in BURNING UP anthology)
There are also couple of YA books in the works but I am sure 2010 will be seeing plenty of steampunk on it's shelves.