I updated Viewer 2 to 2.7.1, but several of the drivers wouldn't extract without an error message. The viewer still runs but i'm concerned with whether or not they will have some sort of impact on SL.
Here's a list:
zlib1.dll
winmm.dll
vivoxsdk.dll
vivoxoal.dll
ortp.dll
libsndfile-1.dll
SLvoice.exe