Fast SOP variation measurement on WDM systems are the OPMDC fast enough?

Orange Labs organized a 6 month field trial to characterize states of polarization (SOP) variations with time on representative links of the future 40 Gbit/s deployment and to enable specifying the adaptation speed needed by optical polarization mode dispersion compensators (OPMDC). The SOP variations speed can reach more than 50deg/1 ms which seems not fully compatible with OPMDC specifications.