DFT reports that an enquiry by Reuters shows that 7 out of 11 analysts believe that the RBS bid will be more successfull. Only 3 believe with a 100 % certainty that the Barclays bid will go through.
My guess: while the majority of the analysts is right, it may not always be about being right analytically. ABN AMRO has a former DNB-manager (deSwaan) in the background and will play some regulatory cards, casting doubt as to the RBS-bid. And with a lot of doubts, a central bank will not be happy, because that may mean a lot of risk as well.