Now it's getting closer...RC1 has been out for a few days. Unlike 2014, there is no 32 bit version and Windows 2012 is required (or Windows 8 for the developer/standard versions). However, some client tools work in 32 bit and on Windows 2008 R2.
In the version I have access to, the stand-alone installation is divided into three parts, the server components, the management tools and the Data Tools (Visual Studio). The last two are only links to MSDN where you can download the installation packages. May of course differ in different releases, it looked the same in RC0.
Another nice novelty is that we can set tempdb directly at installation, it suggests the same number of data files as there are cores in the machine
Will be interesting to see what it says if you have a few more cores in the machine like a real server.
RC1 has version number 13.0.1200
Here is a list of all new features in RC1: https://msdn.microsoft.com/en-us/library/bb500435.aspx