Thanks to a couple of extremely talented hackers/overclockers, new custom 720MHz and 800MHz Linux kernels have been released. The overclockers, unixpsycho and caj2008 have done a fantastic job in allowing users to squeeze the most out of the Pre.
The details on how to accomplish this are at the link below. Do this at your own risk. You could fry your Pre if you're not careful. That said, many users have tested this procedure and it seems to be working for them. Many users note the Pre "screams" now and is "insanely fast." We wouldn't go that far. It is an improvement but compared to the experience on an iPhone the Pre still seems slower.
If you're ready to take the plunge read through all the instructions. It gets a little confusing but just keep this in mind while reading the instructions: WOSQI = WebOSQuickInstall. You download a file from the overclockers, then load it on your Pre via WebOSQuickInstall. You can find out more about WebOSQuickInstall at the link below.