The latest issue of NTS has an article by Campbell on Galatians 5:11
Douglas A. Campbell, “Galatians 5.11: Evidence of an Early Law-observant Mission by Paul?” New Testament Studies. 57:3 (2011): 325-347.
Campbell argues that Paul originally taught a “fully law-observant gospel” to Gentiles that included circumcision but later changed his mind and taught against that view. Personally I think this conclusion is untenable because the “offense of the cross” was always there but feel free to read his article and refute my ignorance!