Harry Potter - Harry is a pretty standard talented-but-immature jock with a chip on his shoulder and something to prove. I think he'd be most at home as a maverick fighter pilot, with a homoerotic rivalry that must be put aside to fight the greater evil (probably a shady east Asian conglomerate, or something).
Hermione Granger - I know she's English, but I can only see her as a U.S. Secretary of State. The equivalent in England seems to be the Secretary of State for Justice in the Ministry of Justice, which sounds appropriately intellectual and badass.
Ron Weasley - Desk jockey at the FBI. Ron's courage and loyalty outstrip his intellectual abilities, which makes him a perfect fit for the Bureau.
Neville Longbottom - That awkward but randomly hot professor who can usually be found holed up in a lab (and that's how he likes it).
|A bazillion points to Gryffindor, hot stuff.|
Luna Lovegood - Vintage clothing/furniture store owner, and an avid pastafarian blogger.
Fred/George Weasley - Second City Toronto improv teachers. Though they'd probably fit in better with the 1973-1974 crowd than anyone in more recent memory.