Mark certain updates as IMPORANT or STICKY

We get a lot of Comments in our update feeds and quite often Important things can get missed. I think it would be great if our users had the option to Make certain comments in the update feed STICKY (which would bump them to the top) and/or IMPORTANT (which would bump up and/or highlight them). Seems like it would be pretty basic functionality to add and could be VERY useful for us and many others.