SystemC is the C++ equivalent that's been around for a long time. For a project I was working on, I used SystemC just for system-level modelling, it didn't bother me that I couldn't synthesize. To achieve decent clock-rates it would have been a good idea to reimplement the whole thing in "native" Verilog anyway (though my project didn't get that far). What SystemC provided me with is a way to sanity-check my model at the "transaction" level.
Pretty cool to see this, and going forward as a roadmap there is much they could borrow from SystemC.
MyHDL is implemented as a minimalistic pure Python library, which basically means that you can use Python features for modeling - pretty powerful. In addition, it supports conversion of a language subset, so that you can also use it as a synthesizable RTL language. The latter feature is absent from SystemC.
Pretty cool to see this, and going forward as a roadmap there is much they could borrow from SystemC.