If a task had three notifications (e.g. a comment, a change of field, and a new task assigned), the 2.0 notifications page would unfurl all three grouped together. In the new Inbox, you just see the most recent notification for a task unless you click.
If it showed the NUMBER of notifications waiting, that would be helpful.
In the example image below, the inbox notification I saw was 'merely' a List change; I was going to just clear it without opening it. But the List change was only the most _recent_ notification; clicking I found the critical other notifications I would have missed otherwise.