The icon switcher currently shows the 6 most recent threads. This behavior is OK, but we can probably come up with better rules for this. In particular, these might be useful:

• Letting new threads jump to the front of the list.
• Letting threads where the user's name is mentioned jump to the front of the list.
• Letting users pin threads.
• Letting users dismiss threads.

This is a lot of time consuming UI work and the behavior isn't very important, so we should wait until the product is more complete before deciding on and implementing rules.