It's not an easy comparison to make, yes. But Go isn't really that low level. It has garbage collector, type inference, unique concurrency support that hides threads... And it's provided on App Engine.

App Engine also supports Python and Java. I figure folks could use Xtend to write Java web apps that cut some of the boilerplate and perhaps even deploy to App Engine, for instance. Giving folks an alternative to going with Go as a static typed language.

Perhaps Xtend using Java source-code as an intermediate medium confuses people a little. Using Eclipse to program using Xtend/Java may just be too seamless for it not to matter much after you've grown used to it.