I've found a bug with the beta release. Open vista style builder, and open your theme.msstyles ( the one I used was the xp luna theme found here:
http://sagorpirbd.deviantart.com/art/XP-Themes-Final-for-Windows-10-520345860 ) then press 'test'.
The bug is that my close/minimize/maximize buttons are now noticeably bigger than before after 'testing/applying' the theme from within vista style builder. Here's a picture:
http://i58.tinypic.com/t82hjq.png