As is expected for this late in the development cycle, this time for the Linux 2.6.37 kernel, it's mostly just bug-fixes. There's PCI resource allocation changes, a V4L update caused when the BKL (Big Kernel Lock) was removed, a large scheduler patch to fix high load average problems with the NOHZ kernel configuration, ARM architecture updates, and much more.
Linus is a bit concerned about the state of the Linux 2.6.37 kernel right now with regressions so there may be a 2.6.37-rc8 release before going gold in the next week or two. Just after the 2.6.37-rc7 kernel was tagged, David Airlie sent Linus some patches fixing DRM graphics regressions, which is one of the regressed areas Linus was concerned about primarily for the Intel DRM.
The Linux 2.6.37-rc7 kernel release announcement can be read at LKML.org.