Play.com has a new 2-disc Special Edition Cloverfield DVD, with an exclusive Play.com cover, listed on their site. The page says "*Artwork Subject To Change", so I'm not sure what to make of this, but they are taking pre-orders... for a June 9th release date.
UPDATE: Just checked HMV.co.uk, and they have it listed too, but with the SteelBook cover. Also, I didn't realize this earlier, but June 9th is the release date in the UK for the standard DVD too.
* Thanks to Amie B for finding this, and to Dave for the date correction!