For starters, developers now have to think about writing cross-device by default. It's akin to the initial push for mobile-friendly websites, with many of the same issues. Those don't just involve multiple display sizes, although that's hard enough -- what looks good on a 5-inch screen looks like a waste of space on a 10-inch tablet or a 21-inch desktop. It's also about having to make good use of multiple input modalities: touch, conventional mouse and keyboard input, and who knows what else comes down the line over time (such as the Kinect).
Designing a mobile-friendly -- or in many cases, mobile-first -- website is a lot easier than it used to be thanks to the frameworks and design metaphors available for that job. While Microsoft would be foolish to not provide toolsets to make such cross-platform design easier, that sort of work isn't something that can be wholly automated. It still falls to the designer to make the hard choices.
3. The cloud is the new development environment, as it should be
Strictly speaking, this isn't news, but everything that's unfolded of late has hammered it home harder. When news about Roslyn finally started to emerge, it became clearer that the technology was meant to be an adjunct to Microsoft's new set of cloud-hosted, Azure-powered IDEs. The more ambitious and cloud-centric the projects developers are working on, the more likely they'll be to reap the benefits of using a cloud hosting system -- that is, the massively parallel load testing and live telemetry offered through Microsoft's services.
It remains to be seen if others will take Microsoft's open source work on Roslyn to develop their own cloud-hosted app environments. Such a move would afford Microsoft yet another challenge in the form of an alternative to their particular cloud (an increasing source of their dependable long-term revenue) and would give developers, Microsoft-centric and otherwise, tmore freedom of choice.
4. Microsoft's development future isn't solely on Windows anymore
This means developers who've typically shunned Microsoft's tools and platforms may find more reason to use a Microsoft original (and, specifically, Windows), without being tied to its origins. The C# and F# languages have already offered some of this, but there ought to be more once we see how Roslyn affects the future of the .Net family. At best, it could prove to be as germinal for cross-platform language development as the JVM has been. If that does happen, Microsoft could finally find itself in the position of not needing Windows, and the culture of software born and bred for it, as its biggest success story.
This story, "Four things developers should know about the new Microsoft," was originally published at InfoWorld.com. Get the first word on what the important tech news really means with the InfoWorld Tech Watch blog. For the latest developments in business technology news, follow InfoWorld.com on Twitter.