Grown-up fans of the Teenage Mutant Ninja Turtles have been more than a little mixed in their take on the new designs being rolled out for Nickelodeon’s latest reboot of the property, Rise of the Teenage Mutant Ninja Turtles. Until today, we’ve only had concept art to look at, but now we’ve got the first official teaser for the series. I’ll let you make up your own mind on it. For me, all I can really say right now is that it’s definitely a new take on the turtles…