A guarantee was presented as a letter by the Bulgarian Prime Minister. In the letter to FIDE President Kirsan Ilyumzhinov the Prime Minister stated that for technical reasons no formal bank guarantee could be provided, but that the Bulgarian government would guarantee the total costs of three million Euros (two million prize fund, 20% FIDE fees and the rest for organisational costs). The letter further stated that "neutrality would be guaranteed".
There were two other World Championship bids, from Turkey and Singapore, but for lower sums. These bids were withdrawn when the details of the Bulgarian bid had been presented. In the vote of the Congress the world championship was awarded to Sofia, by unanimous decision.
The match is scheduled for April 5th to 24th 2010. April 5th is the birthday of FIDE President Kirsan Ilyumzhinov. More details to follow.
Addendum: FIDE corrects our report: "Please note that the exact dates in April 2010 will be set and announced by FIDE after consulting both players and their schedules," writes George Mastrokoukos.