I've been on a desktop PC since I first started using a computer regularly, probably 10 years ago. I agree with a couple people here that stated that it's nice to be able to walk away from the desktop and take a break every now and then. I also like having my desktop plugged into my television and surround sound system for excellent entertainment.
I've never had a laptop of my own, but I think I would really enjoy having one. It would give me the opportunity to go sit in another more comfortable room and chat with friends if I've having a lazy day. And more recently, I'd be able to take it with me to meet with a current or prospective client - no more jotting down in notebooks and such.
So basically, I think it's the best of both worlds. Just wish I HAD both worlds