macvim
terminal or iterm
transmit or yummy ftp
get vm for windows for testing ie6/7/8/9/10
https://github.com/xdissent/ievms/
marsedit for adding wp/blog posts
sequel pro for mysql stuff
colloquy for irc
and install xcode then download the command line tools (plus probably get macports so u can easily install *nix based stuff)
xampp for local server (easier than using built in php..)