I just took the GWave survey at https://survey.googleratings.com/wix/p3726709.aspx

I guess i'd noticed it but didn't realize how much scrolling sucks in wave. I thought this GTK demo would be a nice concept to implement:
http://thorwil.wordpress.com/2008/05/09/popup-scrollbar-concept-demo/

P.S. I now have 100 contacts in wave! This is spreading pretty fast =]