Nikon USA sent out a service advisory early this morning via email to registered owners of the Nikon 200-400mm f4 Lens - apparently there has been a problem with the of the case cracking, and to quote Nikon:
It has recently come to our attention that select components incorporated in some CL-L2 Semi-soft cases may be compromised. This may result in cracking of the bottom of the case. In a worst-case scenario, the bottom of the case may fail. Should a failure occur, the case's contents would be subject to release and possible damage. Nikon has studied this issue thoroughly and steps have been taken to effectively correct this issue, assuring the quality of CL-L2 Semi-soft cases going forward.
Having your $5,500 Nikon 200-400mm f4.0 lens "be subject to release and possible damage" would be less than ideal, so if you own this case, it's worth checking.
If the case has a letter "T" stamped on the bottom (mine doesn't), then you have a newer case that is not effected by the recall. Owners of other cases should follow the instructions below:
To obtain a replacement CL-L2 Semi-soft case:
If you own a CL-L2 Semi-soft case affected by this issue (without a "T" imprinted on the bottom of the case), please follow the return information available from our website at: http://www.nikonusa.com/cl-l2 or contact the Nikon Customer Relations Department toll-free at 800-645-6687. Calls will be received Monday through Friday, between the hours of 6am-4pm, PDT.