Here's the list as I see it (+ what we already have, some of which are listed here):

• Parallel builds
• Forced, triggerd, polled, scheduled builds
• add/copy/edit/delete project
• view changesets
• view built artifacts
• view/repeat historical builds (based on SCM @ date or tag)
• view junit results (expand to other reports later, or just use a generated site)
• stop build
• browse working copy, delete working copy (clean checkout)
• project grouping
• RSS
• HTML mail notification
• security

I'd like build promotion and deletion, but that might have to wait.