With Thompson Reuters' of release of 2007 data for Journal Citation Reports, BioMed Central is announcing new impact factors for BMC journals, which "will include the first official Impact Factors for 12 BioMed Central journals, as well as updated Impact Factors for 28 more. Using Thomson Reuters citation data, unofficial Impact Factors have also been calculated for more than 100 BioMed Central journals, and this information is now listed on our Impact Factor FAQ page."