Download the trials:
- Visual Studio 2010 Professional Trial (ISO – 2.16GB)
- Visual Studio 2010 Premium Trial (ISO – 2.24GB)
- Visual Studio 2010 Ultimate Trial (ISO – 2.25 GB)
- Visual Studio Test Professional 2010 Trial (ISO – 408 MB)
- Visual Studio Team Foundation Server 2010 Trial (ISO – 1,56GB)
These trials last for 90 days. After the first 30 days you must register your trial version to obtain a free key so you can use it the additional 60 days.
For release notes, list of new features and improvements, I refer to Scott Guthrie's blog and Scott Hanselman's blog.