I think for now I'll continue down my current path. I like to code, and I like to design, and I happen to be decent at both, and I think I would be disappointed if I was somehow forced to give up either. So why not continue? It's served me well so far.
I may never be able to hang with the hardcore code slingers or the hardcore designers, but there's a ton of spectrum between the two extremes that is largely ignored, and there's value to be had there. As @idan pointed out, it might take some self-promotion and/or time to prove yourself (assuming you're aiming for work at an agency or other established company), but once you carve out your spot it will be clear how much value you provide.
And of course if your plan (like mine) is to strike off on your own, then who cares -- you'll get a ton of mileage out of a mixed skill set. You can always hire 'experts' down the road.