As promised, a second snapshot of siunitx version 2 is now available:
This adds functioning unit processing to the test code, as well as sorting bugs in the previous snaphot (for example, a few problems with numbers). Testers will see that version 2 will provide a lot more units by default: this is a result of changing the method for defining units, making it much easier to avoid clashes with other packages. As with snapshot one, there are a lot of gaps in the existing code (for example, backward-compatibilty!). Feedback is very welcome.