Update 2009-02-24 This is now a public beta from Apple.
If you are registered as an ADC member (go to http://developer.apple.com/ then to the ADC member site link to register for free), you can now download the Safari 4 Developer Preview.
This this is very fast and very compliant: 100/100 on the Acid3 test. (Firefox 3.0.5 scores 71/100.)
First Direct online banking now works fine (and fast).