Kip,
I think specific policies are required for notebooks to cover issues which don't apply to a desktop in the office. For example, we don't want our staff to leave their notebook in a car, at any time!
People tend to use a notebook for more personal stuff than they would a desktop in the office, simply because they take it home - so loading additional software can be an issue (that's a bit easier to control on a desktop in an office environment). That's the sort of thing that can cause problems back in the office environment.
Then there's the security of the data - a notebook is much more at risk of being stolen from someone's home than a desktop PC in a secure corporate environment. But there are ways to protect the data from the average person who steals a notebook (or the person they sell it to!). That's more an issue for the IT Dept. but the end user can undo some of that stuff (like removing password requirements).
Once a computer is taken out of the office environment it becomes more vulnerable to viruses and hackers. Most viruses would be stopped at the corporate mail server and hackers blocked by the corporate firewall, but once you take a notebook home and connect to a domestic broadband connection the level of protection is unknown.
There are a lot of potential issues once staff start using notebooks!
If anyone has any policies specific to notebook use please share your thoughts
Kevin