That's going to start slowing down, now that the IRS has caught on.
http://www.irs.gov/publications/p936/ar02.html#d0e2092
Short answer: there's now a limit to how much "home equity" debt you can deduct. In particular, people who are tapping 'present value equity' (as oposed to paid-in equity) will lose the deductability of such tapping and, hopefully, will be less likely to incur it in the future.
/jordan