The kernel is designed for Mac OS X Lion 10.7.3, the newest version of Lion, and it supports the AM2 and AM3 sockets for AMD processors. Right now, the kernel can only be run in 32-bit mode, so several 64-bit system applications in Mac OS X Lion don't work. Most importantly, Finder doesn't work-- though you can easily use a Finder replacement such as Path Finder.
For those who don't know, the kernel is a file that Mac OS X uses to communicate with the processor. Apple only designed Mac OS X's kernel to work with Intel processors, since that's what real Macs use. Hackintoshes with AMD processors have to use a modified version of the kernel to work. In the past, the most popular modified version of the kernel was the "legacy kernel", made by nawcom. However, nawcom's legacy kernel only works with Mac OS X Snow Leopard (nawcom was unable to update the legacy kernel for Mac OS X Lion due to medical issues). This new legacy kernel was developed by a Russian Hackintosher called Bronzovka, picking up where nawcom left off.
Since this new Lion legacy kernel is still in beta, its usability is very limited, and it should mostly be taken as a proof of concept. Right now, there is essentially no support (at all) for installing Mac OS X Lion with this kernel, so if you're not very experienced with AMD Hackintoshes, it's recommended that you hold back on the kernel until it's out of beta.
SOURCE: mach_kernel 10.7.3 for AMD