It seems that around here, 85-90% of bands do covers, young, old, inbetween, mostly covers.
There's a few bands playing their own songs, but not many unfortunately.
Personally, I've always found doing covers a bit boring, because "you've got to play it like the original", some of the best covers I've heard have been a bands interpretation of a song, played in their style.
I remember being "berated" by the guitarist of a band I was in, because I wasn't playing the song right. "Which bit", asks I, "the pauses in the bit there are out, you aren't playing it like the original". Pretty much sums up my experience of doing covers "You're not playing it right", sorry, but I bet the band that recorded the song originally never quite play it "right" either.