I went with a Thinkpad laptop; I got a SL500 as the best combination of comfort, price, screen resolution (1680x1050!), and immediate availability. To its right is a Wacom Cintiq 12WX. These two components are going to be used primarily for remote communication--- shared whiteboard, videoconferencing, WebEx, etc. The laptop will go with me to California as a development machine, too. (Not shown but also new: $60 8-port Gigabit switch from Netgear. Had some fun tonight trying to figure out why it didn't like one of my cables. Best Buy's cable prices are outrageous but I shelled out $21 for 7' and $30 for 25' anyway because my bulk box is empty.)
The middle monitor (a relic from a Fry's sale) is hooked up to the cheap Gateway I've been using to do development and run experiments. I've been accessing the company VPN and intranet from that machine, and using the right keyboard and mouse to do so. With the new laptop, though, this is uncomfortably off-center.
The far-left monitor, hooked up to my personal machine, is where I do most of the work. It has its own keyboard and mouse which I prefer using, and the monitor has the best quality of any of them.
It's probably time to try out Synergy again, so I can just use the same keyboard/mouse everywhere. But I wasn't too happy with it in the past.
My old configuration was to put the cheap monitor on my home machine and do most of the work on the laptop in dual-monitor mode, but the laptop's already in dual-monitor mode with the Cintiq. I'm thinking that it might make sense to just hide the Cintiq (maybe stash it underneath the desk) unless it's actively in use. I am also considering moving the Gateway box downstairs and just accessing it remotely now that I have the laptop. Then I could remove the CRT from my desk, too.