I often use the SLV Development viewer. I’m on one of the version 2.8.3 builds. So, I have a sense of how well it is or is not working. But, that tells me nothing about planning for the viewer. For that information I rely on the Office Hour or as it is now called the Viewer Evolution User Group meeting. Recently that meeting has not been happening. Actually for the last two weeks the Lindens are not showing up. This group was one of the most informative and communicative. Now it is one of the worse if not the worst. So, it is hard to know what is going on with the Linden Lab viewer.
Viewers to be Blocked
Opensource Obscure noticed in the wiki a note in the 2.8.0 viewer release notes about versions of the SLViewer 2 series being blocked. Viewers from version 2.1.1 to version 2.6.8 will be blocked at logon. As the Lindens have promised the 1.23.x viewers are excluded and will be able to login.
I think there are enough code changes and new features in Second Life that one needs a 2.7 or better viewer to get the most out of SL. The blocked viewers are using support services that will likely be turned off in the coming days.

