As nice as it would be to take a hat full of youngsters and build for the future, it just won't happen.
It's Capello's last job in management and he'll want to give it his best shot at winning something; and the FA wouldn't want to risk further embarrassment by taking an inexperienced squad and being humiliatingly knocked out in the group stage. The blame will pass onto players and management again should we falter with our strongest squad.
Also, not many of the youngsters are ready for the step up, and I presume many will be taken to the Olympics rather than the Euro's. Players like Cleverley, Sturridge, Welbeck, Henderson and Rodwell, the future of England, struggled somewhat in the U21 tournamant last year. Some may have a chance if they maintain their form, particularly Smalling, Jones and Sturridge.