I've been working from home for five years now. It has its perks but I do miss some things about working in an office.

Mainly the clear demarcation between "work" and "home." Working from home I just make myself some coffee, walk upstairs, and I'm working. Or not, I may go down and work on my car or clean the kitchen. Working from an office I had the drive to clear my head and go into work mode. And then the drive home to get back into "home" mode. I couldn't let "home" bleed into "work" and vice-versa.

I also miss being able to go knock on someone's door and bounce an idea off of them. Now I have to type it out or fire up a skype session to discuss things. Typing in the chat room isn't easy and nuance is lost. And the effort of bringing up a skype session and the human niceties that tend to go with it (the "hey how are you?") and technical problems ("you need to upgrade!", "internet is slow!") make it hard and I tend to just not do it.

That said, working from home on my own projects is nice and I don't know if I could ever work in an office for someone else ever again.