The multiple-terminal support in Emacs 23 (CVS) means that I can leave my main Emacs session running on my laptop, connect to it from the desktop using SSH, get a graphical display on a big screen, and still be able to use my laptop if I decide to go off wireless. It also allows me to fake having a dual-screen Emacs setup. =) Very happy. This will be good for when I'm writing WickedCoolEmacs, too.
I used the great scripts from Enigma Curry: Multi-tty Emacs on Gentoo and Ubuntu to make it painless.
Random Emacs symbol: pcomplete/eshell-mode/eshell-debug - Function: Completion for the `debug' command.