One thing I noticed when starting to work with SharePoint 2010 in Visual Studio 2010 is that when you are editing a master page (and some other type of items) you get no intellisense.
Why this is I have no idea but I can guess that it has to do with the project type that the SharePoint project is based on (getting back to that in upcoming posts…) which is not a web template.
OK, but you can get around it thought.
What you do is right-click on the .master file and choose “open with…”
Then you click the “master page editor” and click “set as default” button.
Now it should work again…