Sean Connery IS James Bond
Roger Moore IS James Bond
Timothy Dalton IS James Bond
Daniel Craig IS James Bond
It's been 27 years since Raiders of the Lost Ark, TWENTY-SEVEN YEARS!!
Since Dr. No is 1962, there have been 5 actors playing Bond. It's patently ridiculous to suppose that Harrison Ford IS Indiana Jones when no one else has ever been permitted to play the character, whereas we all perfectly accept all these actors as Bond or all the actors that have play Batman over the years.
William Hartnell IS the Doctor.
Patrick Troughton IS the Doctor.
Jon Pertwee IS the Doctor.
Tom Baker IS the Doctor.
James Bond is a Time Lord; that's why he keeps changing his face while maintaining the same identity. Indiana Jones, however, is a plain Human and will always and forever be represented by Harrison Ford. How happy would anyone be if, suddenly, Darth Vader's voice was done by Matt Frewer or Owen Wilson instead of James Earl Jones?
We all get old. Seeing a late-middle-aged Indiana Jones is somewhat comforting. I'm 36 and beginning to realize I'll never be as hot and spicy as I was when I was 26. It'll be nice to see that even a Nazi-busting hero can get some grey and still lay down an old fashioned ass kicking.