Don't forget:

Native shortcuts to take various screenshots (unrelated to anything, but so useful and cool): http://guides.macrumors.com/Taking_Screenshots_in_Mac_OS_X

* Sparrow http://sparrowmailapp.com/ - Gmail done right

* TextWrangler http://www.barebones.com/products/textwrangler/ - Best text editor, for any purpose and free

* Pixelmator http://www.pixelmator.com/ - Mac equivalent of Paint.NET except it's not free. Worth it though!

* Transmit http://www.panic.com/transmit/ - FTP, SFTP, you-name-it client

* LittleSnitch http://www.obdev.at/products/littlesnitch/index.html - Software firewall for when you want to block certain apps outgoing web requests

Enjoy your new Mac!