1) what are their favorite teams? any rivalry? (like she's cubs and he's white soxs?) work team(s) in -- logo
2) score board: their first names -- wife's winning of course.
3) colors of everything but grass -- their team or wedding colors.
4) ads all wedding related (the knot, jewelery store, their reception all, honeymoon destination
5) Take me out to the wedding. (Name of bride) has caught him now.
other random thoughts:
umpire calling them both out of the dating game?
figures of him in baseball uniform and her in a dress that is a takeoff on the uniform?
her catching the ring in a glove -- he having batted it to her?
some kind of pun/play on words -- home run? grand slam?
if you google "baseball wedding cake toppers" lots of cute ideas and even some premade one (tho' pricey!)