I believe practically no one *really* knows yet the inside story - although we should see more in a couple of days. Remember that an 'understanding' may range from outright European acquiescence to an arrangement where the opposition is pro forma (with perhaps an understood qui pro quo). [BTW Allan Larson has left the Under-Secty of State job, in fact most of those posts have been vacated for Rice's selection.]
The Europeans are not under the same news cycle pressure to react and/or are keeping mum. There are doubting quotes from the German and Sweedish ODA Ministers (equivalent to USAID) but it is the Finance Ministers who are the WB players. Le Figaro (right wing, close to the govt.) says the approval is just a formality; Le Monde mostly looks to the mixed reaction in the U.S. papers (!) along with the 'we take note' statement from Chirac.
The Japanese have already jumped on board. The Chinese have said they 'will work with whoever is appointed'.
One would have to speculate that this is pretty much a done deal. For one thing Wolfowitz is no fool - he knows that once he agrees to leave much of his leverage is gone. To avoid being left twisting in the wind he is likely to have insisted on a lot of preparatory work (and maybe offering a high quid pro quo) before he took the final plunge. ... But mistakes are made so lets see.