Chetan's web scribblings!

Better Ajax (e.g. ClientID in webforms, clean HTML emission)
Better Entity Framework
Better WCF, WF and WPF (specially DataGrid in WPF)
Covariance and Contravariance
Code Contracts
Charting in ASP.Net
Dynamic Language Runtime and dynamic keyword in C#
Generate code element from usage
Improved Intellisense and Code navigation
Managed Extensibility Framework
Memory-mapped files
Multi-Monitor
MVC (Area and Asynch controller)
Named and optional argument in C#
Office programmability
One-click Deployment
Profiling, Debugging and IntelliTrace
Routing
Silverlight Capability
Text templates
Type equivalence
Visualization Tools
XSLT Profiling & Debugging and XSD Designer