Nokia Lumia 610_groupHot off the press from Mobile World Congress in Barcelona is the news that Windows Phone will be rolling out across another 23 markets and the engineering team have done the work to optimise Windows Phone OS to run on lower-cost hardware.

This means devices based on the SoC (System on a Chip) architecture and with less memory (256MB vs the current 512MB requirement) paving the way for lower cost-devices without sacrificing the amazing Windows Phone experience.

ZTE Orbit 1_croppedOne device announced that will take advantage of these enhancements is the new Nokia 610 (joining their existing line-up of 710, 800 and 900). Also announced is a new device from ZTE, the Orbit.

What does this mean for developers?

Well for one, that’s a massive increase in the market opportunity for your apps. Overnight (well not quite overnight – we plan to open up these new markets over the next month) these changes will result in almost 60% more potential customers for Windows Phone.

But there are also some technical implications

It’s important to test your apps running against the 256MB footprint as well as making some other changes to ensure your apps perform well on these new devices. There’s an update to the SDK (7.1.1 available now as a pre-release CTP) that includes a 256MB emulator image to enable testing. You should also review the MSDN “What’s new” documentation and “Developing for 256MB Devices” as there are some other implications.

If you decide that your app is one of the few that wont / can’t run on the new devices, you can opt-out via the App Manifest by adding a Requirement with Name "ID_REQ_MEMORY_90”. This prevents users with 256MB devices from seeing your application on the Marketplace.

And remember that it’s up to you to indicate that you want your apps deployed to these new marketplaces as they come on-stream. It doesn’t happen automatically. You need to make this happen via AppHub.

More details in Terry Myersons’ post on the Windows Phone Blog and Joe Belfiore’s post on the Windows Phone Developer Blog.