Still going, but not as strong. Some of the main Alt.NET pushers have recently posted rants similar to this one, and are moving on to Ruby and other "communities". In some cases it's sad, as we're losing some talent that, if they could move beyond the negativity, would be just what the .NET community needs. In other cases, we're better off with them leaving, IMHO. Too negative for what ever talent they may have to be helpful. They can move on and poison what ever "community" they move into next.
We don't need Alt.NET. We need Boost.NET (http://www.boost.org in case that didn't make sense). A group that will lead by example, with professionalism, and leadership that works hard on the diplomacy. A group that embraces open source and corporate alike (I used lowercase for both for a reason).