My '99 will hit 41,000 miles soon and my seating surfaces still look pretty good IMO. I have heard about a leather care product called Lexol, maybe you want to try that.
But, hey the seats are going to show some wear over time regardless of what you do, I figure this is just normal. I am not too worried about it.
http://www.autosupermart.com/shop/lex01015.html