I am hoping JetBrains folks will port their suite of .Net tools to other platforms. Since the core of these tools is already cross platform (JVM-based), it may happen faster than Microsoft does to Visual Studio.
Most of the JetBrains products won't be relevant when Roslyn ships. Visual Studio 2015 already ships with many ReSharper features out of the box, with the ability to add the missing ones being made trivial by the new Roslyn APIs.
I definitely won't be running ReSharper in VS 2015.
I definitely won't be running ReSharper in VS 2015.