I just found this quote:
Thus, while it is incorrect to say that the impact factor gives no information about individual papers in a journal, the information is surprisingly vague and can be dramatically misleading.
(Adler et al. 2008)
The report is a very critical discussion about the use and abuse of impact factors and the h-index.
Adler, R., J. Ewing, et al. (2008). Citation Statistics : A report from the International Mathematical Union (IMU) in cooperation with the International Council of Industrial and Applied Mathematics (ICIAM) and the Institute of Mathematical Statistics (IMS), Joint Committee on Quantitative Assessment of Research. 26p. http://www.mathunion.org/fileadmin/IMU/Report/CitationStatistics.pdf