I just heard an interesting fact about why adidas named the F50 this way! Apparently it is to celebrate 50 years of leadership in innovative Football boots. Yes, it's true: adidas has been leader in Football since 1954, when they first introduced the screw-in stud and Germany won the World Cup with them!!! Kinda nice that Adi's reputation isn't build on flashy ads but just on good boots for over half a century...
Actually you're right! The F does stand for Formula and is inspired by F1 racing... However the name originates from the fact that adidas wanted to do something special for 2004. Basically an innovative boot that equalled the screw-in stud boot of 1954.
Be on the look out for an "Adidas F-50 AllStar" team soon. A freind of mine went to San Deigo with his cousin and his cousin got selected. It's sorta like the f50finalround.com thing, just with youth players from the states.