> I think a language should be developed together with its tools.

A lot of people will probably not like this answer, but Go's "tools" are the Acme editor and the shell. If you're running on Windows, Acme-SAC (https://code.google.com/p/acme-sac/, or just running Acme under "vanilla" Inferno) is a viable option, and is written in Limbo, a precursor to Go. (It still has some features Go lacks, but is roughly comparable.)

I wouldn't hold my breath on getting former Bell Labs guys to work on a graphical debugger or Eclipse support, so the language is somewhat unlikely to be developed together with those tools.