[Feature request] Users' collections

Tried searching, but didn't find any collections request. I'm trying to get used to D* after G+ :) And the main feature I'm missing, is G+ style Collections. It also can be achieved through hashtags, but then it would need to change the following system (adding tags/persons excludes).

What I'd want, is to follow a specific tag only from specific people or even one person. Also sometimes I'd like to follow a person except posts with specific tag from that person. There's no way to achieve this now. G+ Collections let me do exactly that, by following some collection or by following a person and excluding any of his/her collections.