This particular release is significant in several ways:
- 64 bit support (x64)
Previously the extensions were installable on x86 machines. As more organizations deploy SharePoint in 64 bit environments and, consequently, developers build in 64 bit environments, x64 support is a welcome change.
- Refactoring for Web Parts
One of the most frustrating elements of the previous version was the inability to rename web parts once you've added them to your project. The new extensions enable easier refactoring by allowing a developer to more centrally rename components without having to chase down all of the files where changes need to be made.
- Solution Generator Compatible with Publishing Sites
If you wanted to easily create a site definition, you could use the Solution Generator utility. However, past versions weren't compatible with publishing (a.k.a., Web CMS) sites. This has now been "fixed."
- Dependent Assemblies included in WSP
The new extensions enable you to include dependent assemblies in SharePoint Solutions Packages (WSPs), so that deployments of custom solutions is easier. This new feature is especially helpful when you have a properly layered application that requires other assemblies to support functionality in a Web Part or other custom SharePoint components.
There are a few other changes that primarily ease some deployment and configuration operations. However, they'll likely have less of an impact on developer experience for more folks.
As we discuss in the SharePoint Report 2009, the SharePoint developer experience is pretty good. Developers often used tools like WSPBuilder to help overcome shortcomings of Microsoft-supplied extensions. It seems, now, that Microsoft has heard the criticisms and is making good on promises for continual improvement. If you're a WSPBuilder user, you may continue to use that utility, but there's definitely a stronger argument for using the Microsoft extensions instead or in addition to other utilities. (This raises another theme we detail in our report: the ecosystem choices you make today have serious consequences tomorrow.)
On the other hand, there are still a few nagging problems with the CTP. However, since this version is merely a minor update to the 1.2 version, chances are good that this new version is quite usable now. Remember though, as with the 1.2 version, it's not compatible with VS 2005.