The Second Life Viewer is getting lots of changes. Even more are to come in the next weeks as the Materials System that allows the use of normal and specular maps. The 3.4.5 version is currently in pre-beta stage, Development. You can download a copy by looking in the left column for: SL Dev Viewer DL.
Second Life 3.4.5 (268856) Jan 9 2013 13:53:27 (Second Life Development)

Download & Install
The file size when downloaded is 29.6mb. It is fast. The viewer installs in its own folder. So, you can have it and other SL Viewers installed without conflict. It also uses its own settings file. It won’t up set the settings on your other viewers.
