In my past job for a large global company, I exclusively worked from home for 7 years.  I was both a development (application) DBA and a production DBA.  We also had development DBA's in India and all over the world.  The fact that we had many people in many places made it easier to work from home because the infrastructure was in place for security, conference calls, instant messaging...  I think that if the infrastructure is there and management supports it then it is worth it.  However many small companies do not have this benefit, so it all depends.

The one drawback is that everyone knows you work from home so they always call you even when you are not supposed to be working.  However, I don't know many DBA's who are not supposed to be working.