You have it right - Dec 31 of the second year after you earn the points.

So, your November 2010 points will expire on Dec 31, 2012. Any points you might earn this year will expire Dec 31, 2013.

I've never heard of anyone being cancelled (and points forfeited) after 18 months. And, yes, redemption qualifies as activity, but it still won't change the expiration date.

I'd also love to hear about ways to extend the expiration date. One dodge that has been reported is to make an award reservation and then cancel it. The points will be put back in your account, but with a new exp date. I think that loophole has been closed.

If the date is approaching and you've got points left over, might as well take a free night somewhere or convert them to airline miles, or get a gas card or something, 'cuz they're goin' away.