I'm not so sure about that, Kev. I'm pretty sure a lot of bands that came later weren't so much as influenced by the Beatles as they were other blues and rock bands. Not that anyone's been MORE influential than the Beatles... but I do think that the amount of influence they've had is vastly overstated in the sense that Beatles fanatics tend to overestimate the number of bands that wouldn't exist if it weren't for the Beatles.
That said, I don't even really like the Beatles a whole lot, but it's pretty silly to argue against their legacy. While I'm not sure they'll be as timeless as those classical composers, they're certainly closer to being so than any other band since the birth of Rock and Roll. That is, if future generations actually place a value on music, which, in all honesty, is something I'm starting to doubt the probability of.