Last night Samsung released the kernel source code for the Verizon Galaxy S III. While it's good that Samsung is making good on timely source releases, this particular bit of code didn't do a whole lot of good in way of GSIII development because of the VZW GSIII's locked bootloader. Fortunately, Team Epic has changed this with a new workaround called kexec hardboot (kernel execution hard boot) that should allow users to effectively "sideload" custom kernels without having to actually flash them on the device by bundling the kernel with the custom recovery.
To demonstrate that the workaround does indeed allow the VZW GSIII to use custom kernels, they also developed a proof-of-concept kernel built from source. It doesn't actually change anything over the stock kernel (there's no need since it's just being used for demo purposes), but it does in fact allow developers to see that kexec hardboot works and experiment with it.
If you would like to download the proof-of-concept kernel/recovery, head right here. Team Epic notes, however, that while the image shouldn't cause any problems, improper installation could cause "irreparable harm" (read: you could brick yo' stuff, so be careful).
It's also worth noting that Verizon could issue an OTA update at any point that kills this workaround, so users shouldn't download any OTA until after it has been tested and custom recovery booting has been confirmed. For more information on kexec hardboot, check out Team Epic's write up.