I don’t know when they released it, but it has a huge amount of fixes and improvements.
The Release notes page says it all.
Edit:
Apparently they did it yesterday.
Today, we’re excited to announce the release of ReSharper 4.1! This minor version is highlighted by:
- Support for Microsoft Visual Studio 2008 SP1
- Enhanced ASP.NET experience
- Improved performance and usability: quicker solution load, optimized Unit Test Explorer behavior, and more
- New minor features, including name editing in code generation UI, generating backing fields for implemented interface properties, highlighting usages of XML tags and attributes
- Stability improvements and bug fixes
See Release Notes for details on bug fixes, cosmetics, new features, resolved performance and usability problems.