I suppose real reason they are not seen that often together outside the Whitehouse apart from events such as the celebrations/ceremonies surrounding the inauguration is security in a post 9/11 world. I think I am correct in that apart from being able to cover more ground it was also stated during the election campaign that for security reasons they did not appear together.
I think you're correct, snugs. Since 9/11 they have avoided being the same place the great majority of the time except where security is very tight (like the White House). Maybe that's being relaxed a little bit, I hope so.
It was great to see the VP get to enjoy that today.