Looks quite similar to Curl (http://en.wikipedia.org/wiki/Curl_(programming_language)), although Curl only runs on the client and needs a plugin. It got a lot of press ten years ago but is now mostly forgotten.

Opa runs on the client and server and compiles to JS, so it got that advantage over Curl. But it's still a kitchen sink wrapper around existing technology, from a single vendor. Those seem to never work out that well.