Confluence is starting to move in on SharePoint's turf, I've witnessed it first hand. The two products really don't compare, but for Digital teams who just want to get something going Confluence is way easier.

I think this acquisition will add to the Confluence vs SharePoint story and make Atlassian more attractice.

IF (it's a big if) Atlassian are planning to move into the intranet/productivity tools space this acquisition is really sensible.