Lukemac,

It does not sound like Asperger's to me either. At 5 DS was obsessed with pokemon, since then the obsessions have cycled through wwII weapons, ebay surfing, Call of Duty, learning Russian etc.
I do empathize with you having to listen to Katy Perry and Lady Gaga all day. My most recent horror is my son's interest in "techno" music and my daughter repeatedly playing "Baby" by Justin Bieber.