When someone adds a comment - it just says "updated X time ago" - it should show:
1. Who created the topic.
2. The last person who edited the topic and when.
3. How many comments the topic has.
This is important - because if someone important (for example the developer of an application) posts a comment in a topic - I want to open it and read it - but currently there is no way on the main screen to know who added a comment to a topic. Please look at examples of forums like phpBB which have developed a tried and tested view that users like to interact with. It should show who the last activity was from.