What we’re seeing here is a strategic maneuver by Dropbox to move up the UX stack from a single file syncing tool to a meta/coordination layer between SaaS products. The goal is to own the user experience and integrate all the adjacent or overlapping SaaS tools in a user’s workflow so you can control both the user and the suppliers.
We’re going to see this more frequently and it’ll look weird coming from different tools trying to level up and pull this off (i.e. what will email look like with this?).
One issue is as incumbents partner/buddy-up and competition heats up, we’ll see a bunch of bundling, increasing consumer costs while locking out newcomers.