Just a note for anyone who's wondering if the release is really going to happen or if the date will just be continually incremented... From reading the wikitech-l mailing list, it looks like the release really will happen and the delays are just minor issues. Here's the latest mail saying that there's a delay for logistical reasons (he later explains it's about organising multiple people):
http://lists.wikimedia.org/pipermail/wikitech-l/2013-May/069471.html
.Ciaran (talk) 09:15, 21 May 2013 (UTC)
This post was posted by Ciaran~mediawikiwiki, but signed as Ciaran.