Headlines on Bloomberg
Bloomberg cite people that said Schaeuble mentioned the idea without endorsing it. Unsurprisingly the sources asked not to be identified and the comments were made at a private meeting. Schaeuble apparently also mentioned how Montenegro uses the euro but isn't a member of the EZ
That's the reason EURUSD has lost a quick 30 pips from 1.1180
Headline shock factor aside, it could well be one of the possibilities lined up if Greece leaves and that maybe some sort of pegged currency deal would be an option
The tone of the comments shouldn't be a surprise as Schaeuble is becoming less positive on Greece actually staying