Is there a big difference between Blu-Ray and 3D Blu-Ray?

I'm not planning on getting a 3D TV anytime soon, but this new "3D Blu-Ray" format concerns me. Is there any real difference? I don't see why there needs to be a special disc, when all that's really needed to really get a 3D HD picture is an HDMI compatible player. I've already started collecting Blu-Ray discs, and it's WAY too soon for this format to become obsolete!