This article on the Reuters website highlights some push back that has come from commodity traders from across the market. It also highlights the claimed cost of exemption loss. Norton Rose Fulbright have summaries on 10 points of MiFID, including position limits and the ancillary activity exemption. There is also another summary of the changes from PWC here.
It is likely that there will be more reaction over the next weeks, and as companies start to calculate their status.