I committed a while ago on participating on that Q&A website whenever it launches.
However, I think it would be better to give
OSQA a try. It works nearly exactly like StackExchange, except it's decentralized and the engine is open source.
OSQA looks nice, almost
too much like StackExchange, feels a bit like a ripoff. What did you mean by decentralized by the way? It's a regular web app that someone will have to host, right?
OSQA is indeed very nice (I ran
an OSQA site).
It's two major pros:
1. You don't need to attract a large core group, you can start it immediately without asking anyone for permission.
2. It's open source, so you can tweak it.
A few disadvantages:
1. You don't get to enjoy the branding/traffic influx of Stack Exchange.
2. You have to set it up and maintain it by yourself.
3. It is inferior to stack exchange, feature wise. I won't go into details, but having used both platforms a lot this is a significant advantage to Stack Exchange over any other Q&A platform (e.g. Shapado, AskBot).
I think at the current rate, the stack exchange site will open in a few months. If anyone thinks this is too far in the future, you're invited to open site based on some other alternative. IMO Stack Exchange is a better long-term solution.
