Microsoft has released a preview of 'Volta', a new toolset which enables programmers to built muti-tier, cross platform web applications. The .NET platform tool is for programmers and aimed at streamling the creation of multi-tier applications. Some are comparing it to Google's GWT (Google Web Toolkit).
Recently Microsoft also introduced Popfly, a Mash-up initiative which we found easy and fun to experiment with. It is worth noting that Microsoft chose to use the .ms domain for that launch.
Will any of these rise to mainstream use. Way too early to tell. The Microsoft Volta Preview is free and requires the recently releases .NET framework 3.5. Be sure to read the known issues, software requirement and limitations. Preview software should not be run on a mission critical computer or network.