Nvidia is working on its 45 nanometre part. Of course this year the company plans to migrate to 65 nanometre as much as possible, but by the end of 2008 it should have 45 nanometre parts ready.
The company first have to shrink its 65 nanometre chips to 55 nanometre, as this is the optical shrink and after this had been done, it will move to 45 nanometre. Intel announced it will go 45 nanometre in late Q4 07 / early Q1 2008, AMD said that for its CPUs it will be able to do it by the mid of 2008, but ATI and Nvidia - who still relies on TSMC - won't have its 45 nanometre parts before the second half of 2008.
The good thing about 45 nanometre chips is that on a 15x15 square millimetres die, you can put 1,350 million transistors or roughly twice as many as you can do with 65 nanometre. Yes we are talking about 1.35 Billions of transistors.
After that the next big step is 32 nanometre, which is scheduled for 2010.