Skey, you may have missed it. It was in the "Some forums are missing..." thread here in General a couple days back.
Here are the new titles, and the post counts for each:
0-49 - FORT Newbie
50-149 - FORT Regular
150-399 - FORT Fan
400-799 - FORT Fanatic
800+ - FORT Fogey
Of course, you can use a custom title (set in your User CP), but if you don't, you get these.