James Newkirk has a post on converting existing NUnit tests to use the new Visual Studio Team System testing framework. It uses the using statement assignment functionality that I blogged about here.
To convert your code all you have to do is something like this:
// using NUnit.Framework;
using Microsoft.VisualStudio.QualityTools.UnitTesting.Framework;
using TestFixture = Microsoft.VisualStudio.QualityTools.
UnitTesting.Framework.TestClassAttribute;
using Test = Microsoft.VisualStudio.QualityTools.
UnitTesting.Framework.TestMethodAttribute;
using SetUp = Microsoft.VisualStudio.QualityTools.
UnitTesting.Framework.TestInitializeAttribute;