A tipster just sent this one in, it's a list of devices reaching end-of-life soon on AT&T, and the Motorola Backflip and Sony Ericsson Xperia X10 are on it. Looks like the Backflip's last day is Feb 2, and the X10 says goodbye on March 6. This doesn't mean that your phone will stop working, or that someone at AT&T won't be able to help you if you hit any technical snags, it just means that they won't be pushing to sell them, and no more new stock will arrive.
On the bright side, AT&T recommends the Flipout and the Captivate as suitable replacements, so they are with us for a while longer. Personally, I say hold off and wait for one of the new AT&T Androids that we've seen this week at CES, or roll with the Xperia Arc as the perfect replacement for the X10 (or any phone for that matter!) -- go big! [sent in via the Android Central app] Thanks tipster!