CEO Drew Houston today announced that Dropbox has hit 200 million users, up from 175 million in July. He later revealed the new Dropbox For Business client securely houses both a user’s personal and work files separately, but in one tabbed interface.

All the new products today are designed to maximize security and convince enterprises that Dropbox isn’t just a frilly consumer tool. Dropbox already serves 4 million businesses and 97 percent of the Fortune 500, but is hungry for more suits.

Today’s news focused on enterprise, whereas Dropbox’s last press event in May focused on developers, and announced it had hit 175 million users, up from 100 million in November 2012. At that event it launched the Datastore API to let app developers save metadata to the cloud, such as a user’s state in their apps (like what levels they’d completed in a game). It also launched the Drop-Ins API to let third-party apps pull in a user’s Dropbox files.

The Pains Of The Double Life

Houston started today’s event by recounting the Dropbox origin story. He was trying to do work on the bus but forgot his thumbdrive and found himself unable to work. He went on to say he hoped there were many things we soon won’t have to do like “carry our little thumbdrives…back up our computers…[and] send emails to ourselves.”

Houston then brought out fashion company BCBG’s CIO Nader Karimi to explain how hard it was to keep the company’s data straight without Dropbox. He detailed how the company can use Dropbox to securely share legal documents.

Drew begins to explain the annoyance of having both personal and work information on the same account. Dropbox originally thought it would just offer account switching, but soon realized that if that takes 15 seconds each time and it has 200 million users, it would waste 1,000 years of its users’ time every day.

“People think there’s this consumer version of Dropbox, and there’s this enterprising version of Dropbox and we think that’s ridiculous. There should only be one,” Houston said. ”To really do this right, you’d have to rebuild Dropbox. But then we thought we’ve hired all these great people, let’s let them rip on it. Now, I’m so excited to introduce the all-new Dropbox for Business. We’ve rebuilt everything.”

The New Dropbox For Business

The new Dropbox For Business client will be rolled out early next year, and businesses can sign up for early access.There was no mention of Dropbox changing its pricing from the current $795 per year for 5 users and $125 per additional user per year.

With it, users can view their personal files in one tab, and their work files in another tab, without having to use multiple windows. If people already have separate business and personal accounts, they can pair them with the new tool. In a blog post, co-founders Houston and CTO Arash Ferdowsi explained, “It’ll be like having your house keys and your work keycard on the same key chain.”

A new notifications bar lets you view alerts from both sets of files or filter to see only one category. Dropbox has redesigned the mobile business client to offer a similar interface to the web for consistency. Developers can also use the Chooser and Saver APIs to let users access any of their files inside third-party apps.

The update puts a heavy emphasis on controls for CIOs and IT teams. The new Sharing Audit Logs feature shows admins exactly who is sharing what with who and when. Security teams can easily block sharing of certain files outside of specific teams, or prevent an employee from having their personal files accessible on their work computer.

Another new feature called Account Transfer helps businesses when they need to remove access to certain files from an employee that’s leaving the company or switching teams. An admin can select an heir to that employee’s files, allowing them to shift all the contents of someone’s business folder to someone new. A Remote Wipe feature also makes sure employees don’t still have access to any of their old business files on any of their devices, and protects data if a device is stolen.

What’s lacking are more collaboration tools available elsewhere, but Dropbox’s Head of mobile and business product Ilya Fushman owned up to that, and says teamwork features are next on the roadmap.

It’s good to see Dropbox continuing to focus on simplicity rather than tacking on a bunch of extraneous products. I liken it to Japanese art of folding steel in swordsmithing– making Dropbox a stronger, purer single weapon rather than making it bigger or adding more blades to its arsenal.

VP of Engineering tells me “When people ask me what Dropbox’s product philosophy is, I tell them this is it. This was a big one to get right.” The company looked at where the most friction in its product was, discovered managing multiple accounts was a huge pain, and expunged this impurity.

If the revamped product is a hit, it could boost Dropbox’s status with lucrative enterprise customers. It earns $125 per enterprise user per year, which stacks up quick vs its free consumer tier and $99 premium personal accounts.

Dropbox enterprise competitors include Microsoft, Google, Box and, as of today, Amazon’s new WorkSpaces virtual desktop enterprise cloud product. But since Dropbox made its name as a consumer product, many businesses have discounted it, going with dedicated enterprise solutions instead.

And really, until today, Dropbox For Business didn’t have the deep permissions and security controls to really make the grade. The battle for the enterprise cloud just got a lot more interesting.