Why is 450 bps important? That is the threshold (as explained before here [3]and here [4]) beyond which LCH goes all medieval on one's bond holdings.
[5]
Either the ECB gets involved here, and fast, and activates the SMP emergency bid, or else the central bank is sending a very loud signal to the country which is now betting Draghi will keep quiet as he accepts Spanish bonds in repo pledged by Bankia.
A signal which is bad to quite bad for those in the cheap seats.