A lot’s been said about Viewer 2.0, two main things that are bugging the hell out of me…
No keyboard shortcut to bring up the IM window. This is bad bad bad! Ctrl T, bam, there’s the chat. With the mouse I have to find the cursor, meander over to the bottom right, click…ugh!
No chat windows in mouselook. WTF? That is terrible!
There’s a lot of good in the viewer, don’t get me wrong, but it seems to have been designed with no thought to keyboard accessibility.
Shuggi's Blog 
Hah! Keyboard short cuts? Sorry, you must have forgotten .. Voice is the new hawtnezz!! you must stand around and show everyone a glimpse into your new life by just using voice
*grins*
Do be aware of the very worrying privacy issues that Shared Media is bringing us
http://stindberg.blogspot.com/2010/02/shared-media-poses-huge-privacy-risk.html
I also find it impossive to actually alt-click anything in mouselook. i know a lot of people do not like mouselook, but for what I want to do in SL, it is a critical skill for me to learn. And being now to SL, I find the almost total lack of documentation on any of the viewers – expect through wiki pages – very frustrating.
Figuring out UIs is not something I am new to. I tend to have a lot of intutive understand of how things work in just about any of them… except for the ones for SL some days…