Updated about an hour ago... by whom?

Description

I often found myself in this situation:

1. I have several issues opened;
2. I have several replies on some issues, but on other issues I still waiting for replies
3. Days pass and I forget if I received a comment or I'm still waiting, so I have to open and check every. single. issue. Wich is very annoying. Very!

Proposal

I have two ideas here, either one would be just fine:

1. Add the avatar of the latest user that replied after the „updated about an hour ago”; (sample)
2. Show a list with last X users that participated in a conversation and highlight the last one. (sample)

Thanks!