The folks over at AndroidPolice are lucky enough to have a Nexus One running Froyo, Android 2.2. You’ve probably seen the slight changes to the homescreen, heard about Flash 10.1 finally coming to Android, make more RAM available for the Nexus One, possibly activate the FM Receiver/Transmitter in the Nexus One, and that it will offer a JIT (Just-In-Time) Compiler for the kernel. Based on a LINPACK benchmark, it shows the Nexus One with Froyo getting 37.5 MFLOPS compared to around 6.5 on a stock N1.
You do have to take these results with a grain of salt though. Not every app will benefit from these changes. Most will probably see a 2-3% increase since JIT only helps programs that are not compiled to native code.
Source: AndroidPolice