Andrew Binstock, for Dr. Dobb's:
Desktop apps, just like Web apps, are also showing the effects of mobile. This is clearly visible in the new designs of icons and dialog boxes. The latter, which were often complex, multi-paneled widgets that required lots of interaction, have now been greatly simplified with far fewer options in a single pane. In addition, the use of widgets that can substitute for typing data values is becoming more widespread. For example, sliders are now much more common as a way to enter values and they will continue to gain popularity. Likewise, spinner controls.
I've seen a similar trend in the past few years. I wouldn't necessarily describe it as 'simplified' since that doesn't quite capture the entire flavor or nuance of what is occurring. A better way, I think, is to describe it as 'focused'. In contrast to yesteryear's 'everything-including-the-kitchen-sink' applications, today's apps are finding success by focusing on the core features and user experience.