One idea we've discussed here before is to embed a bug-report link into every ACS-backed page. Ideally, it would be group-scoped and subsite-aware so you could turn it on only for the right people on the right pages. In an ideal world, the bug report feature would automatically log who submitted the bug, when, what page they were on, and what page they just came from, in addition to having fields that the users could fill in to describe the bug.
This, obviously, would be a compliment to an automated testing scheme, not a replacement for one. But if you tied it into the SDM and the workflow manager in 4.0, you could greatly increase the chances that a given site is properly and thoroughly reviewed before launch.
