I propose to add something like the following to the FAQ text:
Why do I see references around the site to "mi.yodeya"?
Mi.yodeya (based on the Hebrew for "Who knows?") was an earlier incarnation of this site that existed on a now-obsolete but similar Q&A platform. When this site started, it absorbed the community and the repository of more than two thousand questions that had built up on mi.yodeya. Now, this site is called "Jewish Life and Learning - Stack Exchange" or "Judaism.SE" for short, but there's potential that it will return to the mi.yodeya brand when it launches out of beta. In the mean time, mi.yodeya is an unofficial alternate name and URL for this site.
Here are some reasons I'm interested in adding this:
Much of the existing content on the site contains references to "mi.yodeya" or "m.y" which may be confusing to someone who's not familiar with the history.
I'd like to make the URL mi.yodeya.com a possibility for use in print advertisements. I think it's a lot easier on the eyes and understandable (to Jews who've heard of the popular Passover song, at least) than judaism.stackexchange.com.
The only time naming the site has come up in meta so far, mi.yodeya got unanimous support from those who voted or commented. If we use the name as an unofficial name, it may grease the wheels for using it as an official brand later on.
What do you think?