They posted this on their facebook page 15 minutes ago:
It shouldn't be long. We'll make an announcement when everything is back up.
Seems kind of slack IMO, BlockChain.info are meant to be one of the big players in the BitCoin industry yet they have had no end of problems over the past week or some, some out of their control, but others; like this downtime, and similar downtime to their APIs is just poor.