WDC of course. No doubt about it when the people promoting it does stuff like this: https://bitcointalk.org/index.php?topic=428859.0

But it's a premined scam isn't it ?

That depends. If you want to believe the rantings of Hazard then this is what you should read: http://cryptolife.net/exposing-the-worldcoin-scam/
On their official forum there's a thread covering Hazard's post and community members confirm that ~200 blocks were premined: http://worldcoinforum.org/topic/852-exposing-the-worldcoin-scam/

The genesis block (http://wdc.cryptocoinexplorer.com/block/1a48c2bf97e0df6d4f03cd5cb0896ef43b04987048fbeb5ab2dc013335e40731) was mined a couple of hours (2013-05-14 04:13:21) after the announcement (2013-05-14 10:48:51) from what I can tell. But this might not be accurate as I don't know what timezone cryptocoinexplorer.com uses.