Right, the market is full of point solutions that keep focusing in only one aspect of the communication problem. Sort of like UNIX command line tools: great at doing one thing, but loosely coupled with other apps you use.

Yammer is great at microblogging, falls short for the rest. Email is great for 1 to 1 messages. Campfire does chat really well. Asana or Trello do tasks. But your data still lives in a dozen places.

I started a company around the very problem you mention, trying to bring together all the tools I used, and we're now close to 250k business users. And, despite the big guns like Yammer, we're seeing our revenue double every 4 months. Take a look if you're curious, it's called Teambox (http://teambox.com) and it brings together tasks, GDocs, chat, wiki-like notes, etc.