The Go team must feel (deservedly) proud. Since the Rosetta Code programs are typically written to be clear, this shows that without resorting to technical tricks and knowing the intricacies of the language and its libraries Go performs better than both Java and Haskell, but of which are often lauded for their speed.

From anecdotal experience, I've written some Haskell code, and compared it to optimized versions. There is a whole lot of knowledge that goes into optimizing Haskell, since you need to know how to make things eagerly evaluate, etc. Plus functional languages make it really hard to reason about memory usage (doubly so for lazy, functional languages).