Two major new phones debuted in Barcelona at this year’s Mobile World Congress: The Nokia X and the Samsung Galaxy S5. One is more interesting than the other, and you may be surprised which one that is.

First, the Galaxy S5. Much as the iPhone 5S was an update on the iPhone 5, the Galaxy S5 is  really just an update to the S4. That’s OK, since phones were reinvented with the original iPhone, and everything’s pretty much been an incremental upgrade since then. Similarly, the PC’s been going through 30 years of incremental upgrades since the original IBM PC with its Intel processor.

The Galaxy S5 sports some very desirable features for the enterprise, including Samsung’s KNOX security (reportedly, more information is coming on KNOX today in Barcelona) and a waterproof enclosure, which should lead to fewer device replacements due to accidents. The S5 also sports a fingerprint recognition module, much like the iPhone 5S’s Touch ID. However, the Samsung version of fingerprint recognition is reported to be harder to use, in that you have to swipe your finger rather than just tapping it; this makes it harder, if not impossible, to use one-handed.

There are also rumors that Samsung will announce its own version of iBeacon, called Flybell, but so far no official word on that.

With Samsung’s dominant market position, and with the Galaxy S series being their flagship product line, you might think the Galaxy S5 was the big news at MWC.

But it wasn’t. The big news is the Nokia X, a new Android phone from Nokia. Yes, Microsoft is buying Nokia, so this may seem very strange.

It gets stranger: the Nokia X runs the open source version of Android (AOSP, or Android Open Source Project), not Google’s version of Android. So it doesn’t have Google Play or Google Maps or Gmail or any of the other Google-branded services. Instead, it uses Microsoft services to replace most missing functionality.

Wait, what? Yes, it’s a Microsoft-ified version of Android (it even looks a little like Windows Phone 8). This is an interesting play on Microsoft’s part, because it shows that Microsoft thinks the platform (i.e., services including maps, cloud, email, game center, etc.) is more important than the operating system in terms of acquiring users.

The Android version that the Nokia X uses is 4.1.2, so you won’t get the benefits of Kit Kat.

This could potentially be game-changing for Microsoft, being that the Nokia X is going to be a very low end phone, and could create a huge spike in users accessing Microsoft services–but it won’t produce a huge spike in Windows Phone share or usage, since it runs Android. And these low-end phones are aimed primarily at Asia, so their initial impact on enterprises in the US will be limited.

But if it does increase usage of Microsoft services, and Microsoft can leverage that usage to get more mobile users on a Windows (Phone) platform, the Nokia X could be a huge game changer.