Darren Bradley (CUNY) has recently written several interesting papers criticizing the fine-tuning argument:
-"Multiple Universes and Observation Selection Effects", American Philosophical Quarterly 46:1 (January 2009), pp. 61-72.
-"Weisberg on Design: What Fine-Tuning's Got to do With it", Erkenntnis (forthcoming) (Download from his site here)
-"Fine Tuning: The Anthropic Objection Cannot Be Avoided" (Still in progress. Don't circulate or cite. Download from his site here)
Well worth a look!