I got that email too. I guess if you're going to lose miles, you could cash them in, but with last week's sale of 80% off, that's a value of $2.00 for 1000 miles. I think that isn't the best deal around for my miles.
BTW, I read over yonder about a new way to keep your ff accounts active. You can play games at this Microsoft site:
Live Search Club - We're Changing the Game
If you get 250 "tickets" from playing the free games there, you can get 100 miles to be put into a number of different airline accounts. I refreshed all my and my husband's accounts.
Check it out.
Sue