Although quite alarming of this proposal, I'm curious as to how they are actually going to implement it if it does pass.

1) How will they truely determine when you started considering a second home the "primary" resident? For example, if you had more than 1 residence in the same city.

2) How will Uncle Sam determine the fair market value of that home the day you started considering it a primary home? Because, the gain is no longer tied to purchase history, but rather than a arbitrary point in time when you decide it was a primary residence, is the IRS going ot staff up appraisers?

Seems like a lot of gray area that accountants and auditors will have a field day with.

I wouldn't worry about it. Folks will quibble over some technicality, and it probably won't pass.