The current system comes with its own IDE or can run as a plug-in to VS.NET. I just downloaded the version 0.60 beta, and I'm pretty impressed. The whole IDE is 3.5 meg and runs instantly. The package is, on the whole, very impressive. It's basically a small VS.NET C# compiler that targets the Flash runtime plugin. Presuming they get it working with something akin to FSCommands (instructions to the runtime engine to do things), I should be able to then plug the resulting code into Zinc and create a first-class executable for Windows and/or OSX and/or PocketPC.
And that's cool. My head's swirling with the possibilities of this one. Java once had such possibilities, but it is today hampered by a class library best described as a "bloated fetid pile" and is damn near impossible to target for browsers unless you write to a spec that's almost ten years old. Flash is very cool and targets browsers much more effectively than Java (when's the last time a Flash applet refused to work because a base class on your system was incompatible with it?), but the IDE is bloated and slow and weird and the language and class library suffers from a hojillion quirks. C# fixes the Java class library problem but requires the .NET runtime and isn't nearly widely accepted enough for web-based applets and has wobbly support on non-Windows platforms.
Will Neo Swiff fix all problems? Time will tell. If anything, it should keep TANSTAAFL occupied for a day or two.