Docverse is one of the most impressive applications I have seen for a while. It seamlessly lets a group of people share any Microsoft Office document; solving the problems of uploading and downloading emails and having multiple copies of files floating around. The video below will demonstrate how it works on both windows and Mac far better than I can in words.
This is going to get some serious competition from Google Wave but remember it is targeted at MS office users and not Google Docs. But the real question is what is office 2010 going to bring to cloud with it's next release. Microsoft have definitely got the capacity to bring this all its users successfully today as proven with office live and applications such as this but hey are very cautious not to kill the goose that laid the golden egg for the minute.
I realise there is a growing glut of these out on the market but nevertheles it is highly impressive and definitely worth checking out here.