UPDATE: 9th April 2008
I have adjusted the charts to show 2300+ instead of 2400+ after feedback due to the small sample size at such high ratings.
I finally got round to scanning the US armory so here we go.
US stats for entire armory: 167,534 active* teams and 390,988 active* players using Personal Rating.
*more than 0 games played
I have changed the chart to use a % similar to the data Kalgan posted, with 100% being the ideal (11.1% representation). What is obvious is just how popular druids and warrs are, with druids reaching a rather silly 240% in 2v2 @2300+.
Hope you find these useful :)