Boot Camp is the last thing you need to worry about.
Yes, Stuffit Expander is essential. It decompresses .sit (StuffIt compression, as common as zip for Macs), but also .zip, .tar, .gz, and about anything else you can think of.
Might want to consider Audium is you use MSN or Yahoo, or just dislike iChat, in which case you need help
Might want to check to see if your phone is supported by Address Book. Address Book actually connects to your phone through Bluetooth, and will notify you on your computer when you're getting a call and who it's from. It'll also let you send SMS messages, and even see the text message from your computer. If not, there's a plugin that's like $5-10 and adds a lot of phones, I'll look it up for ya.
Download Flip4Mac. A plugin for WMV to run in QuickTime. Don't ever, under any circumstance, use Windows Media Player. Even Microsoft has given up support for it and recommends Flip4Mac. Might want to install DivX codec as well.
Mactracker is awesome in so many ways. You'll never regret downloading it.
Toast is the most amazing DVD burning app in the world. The built-in support might be good enough for you, if not get Toast.
Transmit is the best FTP program on the market, hands down. CaptainFTP comes in close second.
BBEdit is the standard for text editors for programmers, if you're into that. TextWrangler is free, if you need a more powerful text editor for some crazy reason.
I use Yojimbo, and love it. But it's not for everyone. Depends on your needs.
Parallels is quite simply the greatest software in the world. Well, if you're using XP. Vista it still has issues, like you can't run Aero or use a boot camp partition. But for XP, OMFG, buy it now. You can run Windows applications without switching over the entire desktop, like they're just another Mac application. Parallels is a dream come true... for you nasty Windows users.
Office 2004 is awesome, better than the Windows version in so many ways. But wait, 2008 is coming out. Unless you come across a copy some how, like one falls from the sky, then install it ASAP.
Might want to ensure the latest version of Flash is installed.
Aside from that, you should get by with most of the installed apps.