Zen isn't going to be out for over a year, since apparently it won't start coming out until Q4 2016. Unless you think you can live with what you have for another year, you might as well get something now if you're not happy with your current performance.
As for whether Zen would be competitive vs. Haswell-E, it's hard to say as there's virtually no concrete information out about Zen right now. In any case Zen will be going up against Skylake-E and Skylake Refresh chips by the time it comes out, and comparing it against any Haswell chip wouldn't be relevant unless you already have a Haswell chip and want to see if it's worth upgrading or not.