I think the best, best feature of Safari, the one that will actually make it complete very, very fast, is the bug-button.
Apple gets our feedback. Directly and on the point. OmniWeb, with its Crash-Catcher, has a similar entity, but it only catches the actual crashes, not the bugs.
My personal feeling is that compatibility issues will be solved within two months time, and that by May we might see improvements to the UI. Whether Apple will include a tabs feature or not: This is one fast developing browser.