Thank you for this awesome tutorial! 
I hope as soon as possible, its 97% sooo..
I think you have to copy the bbp-twentyten directory from:
/wp-content/plugins/bbpress/bbp-themes/
to:
/wp-content/themes/%nameyourdir%
then you can activate the new theme from Appearance after this you can edit the style.css at /themes/%yourdir%/style.css
Hi!
Dropbox’s forum is quite nice, I am also trying to make a look-alike forum.
You have to play with the css 
