Thanks for the link Mike!
The US Secret Service has put out a tender for the design of a new Presidential Limo. My guess is that there has probably been a huge spike in the number of death threats directed at the President.
Quite honestly I would expect all pretense to be put to the side and we'll soon see the President traveling in a highly modified MRAP with perhaps a "personnel lift" to help him get inside. Its really the only way to improve survivability at this point. The doors already appear to have at least 12 inches of armor on them and if that extends all around the passenger compartment then you're looking at a vehicle that's approaching at least M-ATV weight right now.
You can read the request here.
Could the vehicle below be the next presidential limo???