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
One request: Please distinguish between accounts which have matching
password/email and accounts that don't match but have no edits so will
be merged anyway. The list of accounts it intends to merge with mine
includes quite a few which I certainly didn't create, which could be
rather confusing (well, to be honest, it *was* rather confusing, I
thought it was a bug until I thought to check the contribs and saw
they were blank).