Hi,
I think the decoupling is a good thing, and definitely increases the versatility of both tools.
And awesome work on D3.js as well =).
However, it's a shame that Cube got pushed aside, as I thought it's quite a nifty tool - there's several pull requests on Github, and quite a bit of traffic on the Issues board, so there's definitely people interested in the project. Still, holding out hope it could get revisited =). All the best!