couldn't be bothered to read the other replies but it seems to me that the endless circle of 'retro' that guitar music is in is inescapable..i mean what more can you do with amplified guitars? We've had everything..clean, dirty, distorted, flanged, looped, white noisy, sitar pedals (hahaha), layered cats. spiky. dissonant. ghostly. i can't think of anything else to do. you can just try and build on the output of all those luminaries that got signed first... take a bit of experimental post punk, a bit of psych, a bit of solo wankage, and some feedback ofcourse, mix it all up, write your own songs. if you're a talented musician and you have the intuitive 'knack' you'll make something that'll resonate with people or at the very best make them go 'that sounds like all those guys but, like, BETTER'.
i don't think 'indie' musicians (and i don't mean indie in the current media derivation) lack ambition, there's just not alot that hasn't been done before. If anything you look around and see how shit mainstream music is (so what's new?) and the dominance of guitar music in the UK charts and you WANT to make a psychedelic concept album about an intergalactic salamander. at least i do.
besides without all these rags devoted to old music how else would the kids get down with the sounds of yesteryear? i know i wouldn't have gotten too far, my father loves opera and my mum spent the late seventies at Christian folk festivals.
if you want innovation, as has been said, you look to electronic music, it's still growing. when listening to a bunch of parts mixed together in a studio i am listening for something that is aesthetically pleasing, structures or changes that i have never heard before.
there's nobody more overplayed or plagarised than the Beatles, but when i heard Rubber Soul or Revolver for the first time it was a similar revelation to what must have been experienced when those records were first released.