I've been having this problem too today, in that my avatar body (but not the head) is totally grey and almost nothing puts it right.
That's on the Standard SL viewer.... Catznip, which I normally use, won't even let me in for more than a couple of seconds without completely crashing.
Some form of official notice about what's going on would be appreciated because it's driving me nuts.
**UPDATE***
OOO... it seems to be fixed.... says she hopefully