Mine got 5.0 right away, but I'm still waiting for 5.0.2.
My N7 was dog slow on 4.4.x and going to 5.0 improved things a little for a few days...but then it became so slow it wasn't even usable. I finally did a factory reset, and the damn thing is running like a champ. Fluid, fast, responsive.
I'm trying to be patient waiting for 5.0.2. After this update, I'm going to do another factory reset and then set everything back up again.
If your 2012 N7 is running slow on Lollipop, try a factory reset. It sucks to have to do that, but an unusable tablet sucks even more.