D is but one language (which does not, in and of itself does not fill a vacuum), and I have serious doubts about the social situation regarding its compilers. However, I think it meets most of the other criteria. It also has a lot of features (but not so ridiculously many as C++), however, I'd say it's closer to C++ than C in terms of language size.

Rust is brand new, pre 1.0, and I'm following it with great interest. I do not intend to use it until the low-level error handling has been fleshed out: https://mail.mozilla.org/pipermail/rust-dev/2012-March/00145...

Qualitatively, C++ feels closer to C than Go in many ways in terms of debugging and system aspects, and many C++ programs are written in the "just enough C++" style, which is very nearly C -- and of all possible evils, that is probably the least-evil one in my eyes.

Notably, C++ and D both have have try/catch/finally-style exceptions and inheritance, and while these features can be handy in specific situations, I think both are not desirable. These also apply to Python, a language I also basically like, but I prefer to not have them.