I actually thought 'Wave for Business' at first glance due to the the more free-form nature.

I thought Pivotal Tracker, but more general.

I only saw a lot of facebook-like streams, avatar pictures and a lot of other bling making it hard to see what's actually going on.

From what I can see it's a lot simpler than Basecamp - it seems to be great for a single view if lots of small things rather than managing the detail of larger things (if that makes sense).