The Beatles did something new. Their music gave teenagers whose parents listened to Glenn Miller and songs from musicals something which belonged to them, which summed up how they felt and couldn't be hijacked by the older generation. Oasis give teenagers exactly what their parents had, except with less intelligent lyrics.
So many bands are moving in new directions at the moment that Oasis shouldn't really matter. Pop today has moved beyond Noel Gallagher's "look, we're the Beatles" posturing. I can't see Oasis shocking parents, redefining pop or making Sergeant Pepper in five years' time. The only thing I can see them doing is reforming 25 years after they've split up.