It has always been a real pain to incorporate extensive SharePoint Unit Testing and Load Testing in a project, could Visual Studio 2012 finally make this easier? It certaining looks like it, here's a brief overview on SharePoint support in Visual Studio 2012.
Load testing – We now support load testing for SharePoint out of the box. This is more involved than you might imagine due to how dynamic SharePoint is. You can’t just record a script and play it back – it won’t work because SharePoint generates and expects dynamic data (like GUIDs). We’ve built the extensions to our load testing solution to parse the dynamic SharePoint data and include it appropriately in subsequent requests. So now you can record a script and play it back and we will dynamically adjust it to match what SharePoint expects.
Unit testing – One of the big problems with unit testing SharePoint is that most code requires SharePoint to be running and trying to run tests against a live SharePoint instance is a pain. So we’ve built a SharePoint “emulator” using our new VS 2012 Fakes & Stubs capability. This will make unit testing of SharePoint components WAY easier.
Read more in the link below