It's not uncommon to show Bond as mortal, but to show him as aging goes against the very meta of the character (although I'm not very familiar with pre-Brosnan Bond, so I might be wrong). In a way, this movie was very explicit about what it attempted to do, and the plot reflected the meta-plot: to show Bond as aging and not quite up to the task, and then deliberately to bring him back to a previous time in which he still has a claim to strength.
In that regard, Skyfall-the-place was probably a bad choice; Bond is a killer, but he's a *social* killer, and he would have been at his most classical Bond in a different setting.
That said, the final scene, while not very well acted or scripted IMHO, was as clear and direct as any good ritual. It was the reset button, a resumption of immortality (or at least atemporality) after a brief pause.
Overall, I think I like what the movie was trying to do (at its most mythical, the King is dead, long live the King), but the execution was crippled by the mass of Bondian tics.
(In terms of race, politics, and gender, of course, the franchise remains as... problematic as always.)