I'm a huge fan of Circus Ponies' Notebook software. It's a fantastic way to keep track of the goings-on of your campaign, and a pretty solid way of organizing information about your campaign in general. It follows the same organizational principles of a real notebook, but it's got pretty powerful search and indexing features, and clipping features, audio annotation. Lots of neat stuff.
I've been demoing Zengobi's Curio for the past two weeks and have been planning for an upcoming gameday adventure using it. If you at all enjoy brainstorming with mind-maps, and collecting a lot of information into one central spot, it's pretty neat. I think I'm goning to wind up purchasing the software once my demo is up.
There's not too much else I can think of. I run Campaign Cartographer in a Windows virtual machine for the few times I want to mess around with a map from the old Forgotten Realms Atlas, and do the same thing for
DDI stuff. It's not an ideal solution, and definitely not something for a DM looking to run off of a laptop battery, but you've got the option. For what it's worth, the Windows 7 RC works pretty well in VMWare Fusion on my MacBook. (I need more RAM, for sure, but it's not too shabby)
Congratulations on your purchase--I think it's a fantastic helper at the game table if you have PDFs of your rule system of choice, or internet access.
One other Mac-thing that I tend to do is have different things on each virtual desktop (Space in OS X terminology). Space 1: Adventure/encounter info; notes on what's happening Space 2: rulebooks Space 3: copies of character sheets.... you get the idea--i'm a big fan of multiple desktops as it makes mutli-tasking a little bit easier.