It's plenty fast for me
Using Safari 3.0 on OSX & WinXP, for me it's as fast as my Camino 1.5 on the Mac (which is to say - fast!) and seems faster than IE or Firefox on Windows: Not bad for BETA software - and a 1st attempt at that. So here's one converted user, won't take many more like me to make some sorta dent.
And Firefox's 15% isn't that flash - given it's supported on multiple platforms, compared to Safari's 5% when offered only on Mac OSX.
For Apple to score a significant victory here, it doesn't need to beat IE market share (which it never will) just gain a big enough toehold to force web developers to properly code their sites; to provide a healthy platform for iPhone web-app development; to further give PC-users a taste of the 'Apple Way' - maybe for some conversions; and simply to weaken MSoft's tight grip on internet standards generally. No other company (maybe Google?) has the ability to do this. I wouldn't bet against them - their recent record is too strong to laugh at.