I don't understand the need to enforce the use of { } and that the if of for line must end with a {. I don't like this writing. My preferred syntax is the one of Pythons, which is the most concise and clear. It seem Go could have used : and indentation as in python instead of { }.
Another puzzling choice of Go is slicing which differ from Python's and D's. In Go slicing is limited by the capacity and not by the number of items it contains. Returning 0 as default value looks to me like an open door to silent bugs.
The way Go handles errors looks original and interesting, but I'm lacking experience to determine how it compares to exceptions from the usage perspective.
From what I saw, I would say that Go is a better C and D is a better C++ where better means also closer. As a consequence Go seams simpler than D to learn and use. Thus I expect we will see much more Go programmers than D programmers in the future. Simplicity has been proven many times to be trump.