Here are the results (image courtesy of Mozilla):
He also adds that there is still some bug in TraceMonkey which makes some SunSpider tests slower. Additionally you should look at this post by John Resig who compares even more JS engines and also uses different benchmarking methods. A very good writeup.
So much for the fact that competition is good for the market. One thing to add might be that Chrome definitely feels faster than any other browser. Of course it’s a fresh install and it has no extensions installed but still. Time will tell how the whole field will evolve.