For new customers looking to develop Windows applications, Visual Studio 2010 is pretty much a no-brainer with little else available to match it. For existing users, however, switching to a new IDE will always be a big decision likely to affect both individual developer productivity and the ability to produce quality code. That said there's enough in Visual Studio 2010 to warrant upgrading, not least enhanced support for the latest technologies such as Silverlight and Azure. Moreover, despite being a major re-write, there are no big changes in the way the product is used. Yes, there are changes to how things work and new features and tools have been added, but they all make sense and make an already usable and feature-rich product even better.