The battle of the customer announcements has commenced. Following soon on the heels of Box’s disclosure that GE had selected that file sync-and-share solution over other alternatives (see Is the tide turning for Box?), last week Dropbox confirmed that Spotify had chosen their solution for its more than 30 offices.

We are going to be hearing a lot of these brag releases in the coming months.

Dropbox adds Spotify to its roster of high profile customers, including BCBG, Eventbrite, Kayak, National Geographic, Sur la Table, Under Armour, and Zendesk.

These competitors — and the long and growing list of other market players, like EMC Syncplicity, Hightail, Intralinks, and Egnyte — are pushing hard to lay claim to leadership roles in the marketplace for file sync-and-share.

I have made the case that file sync-and-share is the heart of the emerging architecture for work technology, offering businesses and individuals the virtual distributed file system that operating systems vendors like Apple, Microsoft, and Google left out in the current and earlier generations of OSes. Those OS vendors may fix that problem in the future — probably by buying the leaders in today’s file sync-and-share market — but in the meantime, users and companies are making their picks, and the players are trying to carve out their territory in the this land grab.

Dropbox has been working steadily on two fronts: landing major client companies, like Spotify, and acquiring technology through acquisition and development. I wrote about Project Harmony recently (see Dropbox Project Harmony is breaking the rules), an effort to have Dropbox users rely on Dropbox document-centered coediting for Microsoft Office documents instead of Microsoft’s. I am expecting that Dropbox will soon be proving apps to edit Office documents too. The company also released a two-headed client recently, allowing users to manage personal and business documents with a single application on their devices. This solves a major headache for businesses, who can now control access to documents on employees’ machines, while allowing individuals to continue to sync and share their personal documents outside of company control.

Dropbox has acquired chat tool Zulip, document coeditor Hackpad, photo app Loom, and Readmill (an acquihire).

I am handicapping this race: Dropbox has the benefit of numbers and momentum, and could cinch the leadership role in the market by releasing the right integration of document coediting and folder-based chat. Even competitors like Apple, Google, and Microsoft have not rolled out anything like that: they all have bits-and-pieces but the winning solution has yet to emerge.

I am betting that Dropbox has a ‘son of Zulip’ solution in the works, one in which users can not only comment within files — a la Project Harmony — but which support a rich activity stream of user comments and work object status changes (‘file XJ7-Project-Memo has been updated by @CarlaJones’).

Whoever brings that solution to market first will gain first mover advantages, and disrupt the battle for file sync-and-share.