Currently, I have ns1 and ns2 on the same box. I'm using win2003 and MS DNS for my dns, working fine so far.

Now that I have a second box, I'd like to move over ns2 to there and have that box just mimic my dns entries off the other box.

Obviously, changing the A record for ns2 to point to the second box isn't hard; neither is going to my registrar and changing ns2 to point to the correct IP.

However - I'm not sure how to set up MS DNS to just read off of my other box. Does anyone have a simple walk-through? I usually just "wing it" with stuff like this, but this seems a bit sensitive to really do anything like that.

Yep, you set up a secondary DNS, and tell the first one that your secondary DNS is xxx.xxx.xxx.xxx and it should do an automatic zone transfer. If you have a mic and speakers, shoot me a PM or Email and I can help you out with that.