TMNT proved to be a big hit. The CGI movie took home $92 million worldwide during it's theatrical run, which is more than 2 and a half times what it cost to make and that's before it even hit DVD shelves. So I believe we all kinda saw a sequel as a sure thing but Steve Murphy the head of Mirage Studio's says that hasn't exactly been the case...
As of two weeks ago Imagi Entertainment (the TMNT movie animation studio) informed Mirage Studios that there was a 50-50 chance of a CGI film sequel. Last week they upped the odds to 70-30 in favor of a sequel, as talks between Imagi and their distribution partners Warner Brothers and the Weinstein Group seem to be heading in a positive direction.
I haven't seen the flick yet although I was a huge Turtles fan back in the day and although I can't bring myself to watch the live action movies these days, I have fond memories of watching them in my youth. The trailer for TMNT looked liked it wasn't aimed at me but instead the teenage crowd, which is fine and all but sadly for me it didn't get me into the theatre. I will catch it on DVD though but I fear it might be a hard watch. source - coming soon, the 5th turtle