A few random thoughts:
Vladimir Putin is probably still in the KGB (IRL he resigned after the abortive coup in 1991). What an ideal nemesis... there is even an ideal picture here:
http://en.wikipedia.org/wiki/Vladimir_putin
Bruce Willis is a service brat and is keen to support the US military - maybe he runs a charity for ex-servicemen?
How many entertainers might get stranded in Europe/Korea/Iran/etc entertaining the troops?
There was a character in the Caribbean module was was a TV star - the bosun from memory. He could easily be replaced by a real character.
I used a few (disguised) characters from Soldier Soldier as NPCs - the players have never forgiven me for having Dave Tucker (can't remember the name I changed it to) in their section - especially when his wife Donna turned up!
Imagine Richard Holmes, Paddy Ashdown or Peter de la Billiere commanding a local town militia in the UK...
Bear Grylls would still be serving in 21SAS...