This is purely an exercise in boredom, aka procede at your own risk.
A comparison of my top ten last.fm artists, 2nd week of June 2005 to 2nd week of June 2008:
2005
Deerhoof, Bonnie Prince, Elliot Smith, Nina Gordon (?), The Beatles, Loretta Lynn, Keren Ann, Ryan Adams, Metric, Arab Strap
2008
Bonnie Prince, Brian Wilson, Anna Karina, Air, Lil Wayne, Matt Sweeney and BPB, Autechre, ABBA, Dexy’s Midnight Runners, Neil Young