I got ColorLab running natively in the public Windows 7 RC today, under Vegas Pro 9 64-bit (yes indeed), and the experience was painless. My ColorLab code is 64-bit safe already, thanks to the Visual C++ compiler checks. There were just a few hiccups (and even one blatant bug) in the DXMedia SDK files.
So the thing is, Sony Vegas as of 2009 still uses smoking hot DirectX Transform plugin technology. It's at least ten years old, DirectX Media saw its last release in the age of DirectX 6 (!), and that's really quite depressing. Why Sony, why? But despite this, ColorLab seems to be working and I'm impressed with Microsoft again. It could have been a nightmare but just... wasn't.
Now I just have to make a 64-bit installer and 1.0 RC2 is nearly at yer doorstep.