Friday I picked up a new MacBook. (I almost bought a Samsung NC10 instead, but wanted a machine powerful enough to run Eclipse/etc.)
So far I have mostly been installing all my favorite Mac apps (Quicksilver, AquaEmacs, Fluid) plus a few developer tools (NetBeans, Eclipse, XCode) plus the usual (OpenOffice, Firefox). Given that my last Mac is an old PPC 12" MacBook Pro, this is a significant step forward. Everything is so snappy, and the bigger screen is a great. I've also moved over from my old Password Safe password archive to KeePassX and a DropBox account to share the password amongst my machines.
I've adjusted to the new trackpad surprisingly quickly. I love the new multi-finger scroll. One of the main uses of this machine will be browsing the web, and one of my biggest complaints about using my girlfriend's MacBook, is the lack of page-down key. The two-finger scroll is a great compromise.
I'm looking forward to getting some time to play with XCode an Objective-C. I started toying around with that on my old machine, but got distracted. Now that my household is mostly Mac (2 MacBooks + 1 Mini + 1 Work PC Laptop + 1 PC Desktop I never use), Mac tools are much more useful.