Ahoy me laddies (and beauties), time for the traditional "Talk Like a Pirate Day" kernel release!
Now, last year we had a full release (2.6.18 was immortalized on TLAP-2006), but this year I'm chickening out, and we're just doing what is hopefully going to be the last -rc release for the 2.6.23 series.
I'm not including the diffstat, because it got blown up by the resurrection of the sk98lin driver - because skge that is supposed to supplant it doesn't handle some of the hardware. Oh well.
Apart from that, we had some mips, powerpc and xtense updates, and various driver tweaks. Things like the USB autosuspend revert should make people happier, and some more clockevents fixes should help suspend/restore on i386.
But the shortlog probably tells it best.
2.6.23 has quite a big change compared to 2.6.22 which includes a SLUB (now becomes the default slab allocator), new scheduler from Ingo Molnar : CFS, better virtualization process, Movable Memory Zone, UIO, rewrite code for X86 asm in C, and still many more. Since it encompasses so many big changes, he wanted to make sure that the regression comes down to minimum (it's impossible to have 0 regression) before he finalized the code and release it as the final 2.6.23 kernel. More detail information can be seen on the Changelog or for better human friendly article, please have a look on KernelNewbies