I admit to being a bit of a slacker when it comes to updating (I aim for at least thrice a week), but that doesn't mean there aren't other TMNT sites run by fans that offer a near-daily dose of Turtle news.
Two of the best, in case you haven't already heard of them, are:
Go Green Machine.org
These folks have been around a while (even advertised their site in actual issues of Mirage's TMNT comics!) and they do a great job of not just covering the odds and ends of the TMNT spectrum, but following the individuals who made the franchise possible with regular updates on the careers of old school TMNT staffers. And contests, too!
Teenage Mutant Ninja Turtles.com
Great, professional site layout and lots of regular updates on the current happenings of the TMNT franchise. I admit to being an old fogey that doesn't always keep up with the latest (my site is more about chronicling the past than anticipating the future), so site's like this one are where I get most of my news. There's also a shop, a fanzone and lots of stuff to keep you busy after you've caught up on the news.