I just posted FlexWiki 2.0 alpha 1 on the SourceForge website. Frankly, I'm rather excited. Although it's only at alpha stage, I've been working on this project for well over a year. After extensive rearchitecture, I'm finally at the point where I can start working on the thing that sent me down this path in the first place: a reasonable security model for FlexWiki.
If you have a chance to try out the new bits, please do so. Keep in mind that they are alpha: things generally work, but you're bound to run into issues now and then. Things that specifically don't work right now are caching (although you could argue it never worked that great in the first place) and SQL Server support. Those will get implemented in the coming months.