This benchmark has been updated with Firefox 3.6 release version, safari 4.0.4 and Chrome 4.0.29
The last data point (October 29th) of Safari and Firefox is from Webkit and 3.6b1 respectively. Since Chrome is only a developer preview it made sense to compare it to the development versions of the other browsers. Webkit changes don't always appear in Safari immediately and there is no published timeline unlike Firefox. Firefox is closing the gap in performance but in absolute terms it is still far behind Chrome and Safari. Both these browsers is 2 times better than Firefox on Sunspider scores. Also in V8 benchmark, Chrome is 10 times better than Firefox, Safari is 6.7 times better than Firefox and Chrome is 1.5 times better than Safari.Chrome is improving its scores in both the benchmarks while Firefox and Safari stagnates in the V8 benchmark suite.
Browser Versions Used are Firefox 3.5.4, Firefox 3.6b1, Safari 4.0.3, Webkit Nightly and Chrome Developer Preview. Sunspider is the benchmark suite of Webkit (Safari) and V8 is the benchmark suite created by Google Chrome developers.