Nothing to see really. Bond prices are set by auction, so a negative yield indicates very high demand, not some doomsday scenario.
The real story is going to be the European version of QE, which I expect to be a train wreck, because their version is, by nature, a political game in addition to its ostensible role of simply being monetary policy. There's no such thing as a "European bond", so the politics some in when the ECB has to decide whose bonds to buy. Good luck figuring that out, because part of the reason the stable Euro countries bonds are going negative is that the unstable ones are toxic.