I use a program called FTP thingy, simple and quick like I like it. For text I just use the build in textedit, but I don't do any programming. There's a VNC viewer for Mac to connect to remote windows servers. Azureus for file sharing.
Also Safari is the best browser I've ever used, hands down. Virtual PC is great if you need some programs that only come on Windows, but last time I checked it didn't come for Mac's with dual processors which is what I have.
I haven't needed any windows programs yet, personally. I thought it would be a pain in the ass but switching to Mac was the best thing I've ever done. I can't wait for the G5 powerbooks, I'm still on a PC laptop.