This is missing something critical: It shows tags, but does not allow to use them like tags. Instead it only allows to use them as categories. One should be able to narrow down results by clicking multiple tags.
I did think about it, but my concern was that because I only take a small subset of top keywords for each channel, it's very easy to create a combination of tags that'll show no results. I'll play around with it and see if it makes sense to implement.
