That is good to know! I would have hated to go into an Apple store and tried to convince them unsuccessfully. I would have walked out, but it would have ruined my day. That's why I have such a difficult time haggling/PM-ing.
Regarding the Microcenter deal, though, does this mean that if I buy the MBP 13 from Microcenter, I'll have the old Leopard OS? And if so, is there an upgrade charge etc for upgrading to Snow Leopard?
Yes, it will have 10.5 (Leopard) on it. However, you can purchase the upgrade to 10.6 (Snow Leopard) for $29, so even having to add this cost in, it's still a great deal for the 13-in. MBP, as the hardware should be exactly the same as the "Snow Leopard" model of 13-in. MBP.
Edit: I should more correctly state the demo model MBP on display at my local MicroCenter had Leopard on in, and not Snow Leopard. Maybe they just didn't update the floor demo models, and the actual units in stock in the back have Snow Leopard. I didn't ask the sales person to check, as I just bought the white unibody a couple of weeks ago.