Little Chance of Change
The only suggestions to eliminate the deductibility of interest on second homes (that I've seen) have been associated with consumption tax or flat tax proposals. With the recent democratic victories in Congress, I wouldn't expect to see any such tax implemented in the near future.
Also, most boats that qualify (as well as expensive second homes) are manufactured and located on the east and west coasts -- both areas that generally go heavily for democratic candidates. Representatives from these states remember what the short-lived luxury tax did to the boating industry, and realize that the loss of deductibility of interest on second homes would seriously impact two important local industries.
Just my opinion.