DotNetNuke announced the first ever CTP release and if that wasn't enough, the release is the first of the C# era. If you have  test environment, please, check it out and give the core team some feedback. This helps everyone in the long run by building a more stable project.

The first CTP release according to Joe Brinkman is centered solely around the C# conversion. He stated "As many people have noted, this is a significant change to the platform and affects all areas of the product.  This is one of the driving factors in why we felt it was important to get this release into your hands as soon as possible.  We have already done quite a bit of testing on this feature internally and have fixed a number of issues in this area.  We also recognize that there are probably still some more bugs to be found that resulted from the conversion."

I personally installed and took it for a test drive and about 2 minutes in the File Manager "blew-up". I was told that this particular component was still a work in progress. I reported this issue in Gemini as others are encouraged to do. Happy testing and I'll add to this as the test progresses.