In what way is this a Haskell eco-system report? It looks like a GHC eco-system report. There is nothing wrong with that, but I think it’s mislabelled. What part of it is not GHC specific?
Cabal has some remnants of support for LHC, JHC, and UHC.
And can any of those compilers compile Cabal?
The GHC RTS and Hugs are part of the Haskell ecosystem, but they are written in C so can’t be compiled by Haskell compilers.
I asked if any of the compilers you mentioned can compile Cabal. Of course they can’t compile C (or Cmm) code.
Sorry, I interpreted your question as implying that Cabal is GHC specific because it can only cannot be compiled with other compilers. To show why I find that irrelevant I replied with an analogy to the GHC RTS and more importantly Hugs, which also do not satisfy that requirement.
As for your question, I’d be very surprised if any compiler other than GHC can compile Cabal.
So Cabal is somewhat GHC specific in that to use it you need GHC. I think that’s unfortunate for a tool that claims to be a Haskell build tool. But the Cabal devs can do what they like. It’s a fabulous tool for GHC.
The GHC-debugger improvements and better backtraces look great! 
Do you plan to write a new blogpost now that multiple home-units will be fully supported?