InfoWorld preview: Visual Studio 2010 Beta 2 impresses
A wealth of additions, refinements, and bug fixes has Microsoft's IDE pumped up and primed for March release
New Help engine
A larger piece missing from beta 1 was offline help. Beta 2 has a brand-new offline help engine that doesn't seem to require the ridiculous indexing overhead of the old MSDN Library help engine and displays information considerably faster than the old engine. It also retains the option to get help online from MSDN, which has gotten a welcome overhaul.
I installed only a small subset of the full documentation locally. Local documentation displays in a browser window just like online documentation, only with a local URI, and generally displays faster than online documentation, a refreshing change from Visual Studio 2008, where the Web search would usually complete well before the local search. When local content is not installed, the new help engine redirects to the online documentation. In all the cases I've tried, this has worked without a problem. Local content can be updated easily as needed.
New language and environment features
I have discussed the programming support for SharePoint 2010 elsewhere, so I won't repeat it here. This beta also supports both Office 2010 and Office 2007 programming.
Silverlight support is baked into this release, with targeting for .Net versions from 2.0 to 4.0. The two-paned drag-and-drop Silverlight designer works well, although the graphical pane often exhibits a noticeable delay as it updates.
Targeting various .Net versions is a major capability improvement in Visual Studio 2010. It must have caused the programmers working on it endless headaches, because it creates so many complicated use cases for the IDE, especially for IntelliSense. Nevertheless, it seems to be working well at this point.
I've been a fan of Test-Driven Development (TDD) for several years. You could do TDD with Visual Studio 2008 if you tried, but it took some manual scutwork and more planning than I could usually muster to keep from running afoul of the overly helpful but confused IntelliSense, which would gleefully and incorrectly complete new names. Beta 2 of Visual Studio 2010 adds support for automatically generating stub classes, properties, fields, constructors, and methods from unit tests. IntelliSense can now be used either in the old completion mode or the new suggestion mode; the latter is much better for TDD, since you are often writing test code that uses identifiers and APIs before they exist.
Programmers using Test-Driven Development can automatically generate types, methods, and fields in a base project directly from the test project where they are being implemented. In addition, IntelliSense can be tamed for TDD by switching to "suggestion" mode from the overly aggressive "completion" mode.