I've been working at home for a little over a year now, and I can tell you it is a mixed bag. On the one hand, you can't beat the convenience of being able to work whenever you want. However, it takes a great deal of self-control to get anything done, because the number of distractions is potentially limitless. Also, it is difficult to separate church and state, as it were.
It's also difficult to work on personal projects with a clear conscience. It used to be that I could work on Argos projects at the office and do personal stuff at home. Now they are the same place and for some reason it makes me feel hesitant to actually do anything - like I'm stealing time from the company.
Which is both true and false at a very basic level.
Right now there is no particularly viable option for working out of the house, but I'm still trying.
Edit - 9/1/11 - I've started using a VPN software to log into a client's remote server to update their Filemaker database. That means I can do basic changes and maintenance from home without making the fifteen minute drive to their office. It's really cool, but it seems to only exacerbate the whole isolation issue.