Earlier today, Samsung made available the kernel source code for T-Mobile's Galaxy S II -- the latest of many source releases from Sammy. Of course, if you're not into developing, hacking, or modding Sammy phones, this sort of thing is of little value to you. However, if Moto is your flavor, and you want to make a beastly phone a bit more beastly, listen up: Motorola just released the Bionic source.
This doesn't really change the fact that the bootloader is locked, but it still might allow for some nice overclocking to be done so we can see how far that OMAP processor can actually go. Hit the link to download.