Major changes in new Visual Studio are:
- Designing, building, debugging, optimizing and publishing metro style apps
- Language improvements for Visual Basic, C#, C++, JavaScript and F#
- Application LIfe Cycle Management (ALM)
- Microsoft .NET Framework 4.5
- IDE improvements like Page Inspector, Intellisense, Search
Here is a good url with 13 short interesting videos which explains few of the new features including new Entity Framework 5 videos.
Read more about the different editions on downloads page.
As usual, Visual Studio express versions can be downloaded for free from here.