Heroes in a half-shell

I caught the second trailer for Teenage Mutant Ninja Turtles recently, and I really want to watch it now. I think the animation is really quite cool, but more important there's the whole nostalgic feel to it.

I was never really a big Ninja Turtles fanatic, but I remember once when I was young, I was hospitalised and my family got me the Leonardo toy (I think my brother chose that, being his favourite turtle), which kinda cheered me up. Although I promptly proceeded to lose his katanas somewhere in the ward (sorry, bro), and a weaponless mutant turtle just isn't that fun a toy.

I've always wondered if the heroes were in a hard shell or half-shell (I hear the latter but the former seems more logical), but this site seems to indicate the latter, so... oh well. Half-shell it is.