Sorry. Not any of the new notifications. We already have a system that combines notifications; it's currently only used for Github and Trello integration messages. Github especially can generate a bunch of notifications when you're manipulating a source code repository hosted there. It's also easy to generate a bunch of notifications from Trello. If you look back at the #trello messages on beta, they're an example of the combining system. And I was wrong about the timing. Right now, it's set so that if there are no additional notifications for 4 minutes after the first one, it sends out the original notification. If it receives a new notification in that time, it resets the clock for another 4 minutes. Right now it only resets the clock once, therefore there's a maximum of an 8 minute delay.

Mark