So one of the points that Amy Babinchak made in AU at the SMB security summit was that each time there was a rule in ISA that said “let the world in” you needed to stop and ask yourself why. RDP from THE WORLD may not be a wise move. You can easily …even without a static IP, limit the access to a range of IPs that represent your ISP. So even if you have a Dynamic IP address, all you need to do is to place the ISP’s range as the “from” access and you will be allowed to RDP to that server.
Concerned that you’ll be on the road and need to connect? Connect first to your server and then to the clients.
But bottom line, review the globe.. WHY do you need it?