Please note that the single user login account merging system is up and
running in a live demo state since Wikimania at
http://test.wikipedia.org/wiki/Special:MergeAccount
If your account on
test.wikipedia.org matches your main one, you can try
it out there and check for conflicting accounts. We'll go into the
opt-in beta for actual logins over the next couple of weeks.
-- brion vibber (brion @
wikimedia.org)