I've just been playing with a 3.8gamma image (got from the Debian apt archive, then pulled in latest updates).

The scrollbars are almost invisible in several settings: it's white on white. This is with the default theme (brightsqueak). For example, a system window on a big pane or the package loader have this problem.

It might be good to tweak this a bit before final release.

Running under XFree86, if that matters.