It has been (too) long in the making, but our major rearchitecting of SharpDevelop is close to being done, with only a few functional areas not in this Beta release:
EnvDTE.FileCodeModel is missing, thus our custom NuGet packages will be broken (T4MVC, MVCScaffolding and EF)
Code Quality Analysis and SharpDevelop Reports are missing (due to a rewrite of SDR)
Please note that Beta 2 is not too far off, and these will be in Beta 2.
As pointed out in the blog post SharpDevelop 5 C# Tech Preview, we are still shipping with C# only in SharpDevelop 5 – and this will most likely remain true for RTM too. (VB.NET will compile, but it won't have code completion nor refactoring) SharpDevelop 5 installs in parallel to older versions, and if you have the patience: give it a dry run with a copy of an existing project (at least backup and/or use source control before you let a beta IDE touch your source code).
For further information on what's new, please consult this list of select blog posts from the team members (I'll be doing a few "What's New" blog posts in the coming days, because obviously these are only a few big-ticket items - check back!):
Read more: Greg's Cool [Insert Clever Name] of the Day
Read more: SHARPDEVELOP 5 BETA 1 AVAILABLE