I sent my 11 month old d600 back 10 days ago for the first time for dust spots. I assume that it would be cleaned and sent back promptly. Now I find that the repair is on a parts hold. I am told that they are replacing the shutter blades unit. The problem now is that they are out of the new replacement parts and I have no idea how long it will take them to get my camera repaired and returned. It seems like the folks at Nikon think that we will just keep being loyal to them. They should have addressed this problem from the beginning ,gotten sufficient supply of the new parts and then issued a recall. The last posting under thre dust issue had the person without his camera for a month! That is unreasonable. Maybe next time it's time to think Canon
Apparently there was an early production problem on some cameras. Replacing the shutter mechanism is the ultimate solution. Others found the issue was resolved through normal shooting and cleaning in 5000 frames or so.
Normally camera companies do not have a recall for a problem. They have a service bulletin to repair centers and make the repair under warranty.
The average time for a repair is 3 plus weeks - and its been that long for at least 4-5 years. Typically parts don't take very long - especially for something routine. When you send something to Nikon for repair, you should expect 3-4 weeks and it is unreasonable to expect something much faster.
I doubt Nikon will refund on a camera over a year old, it is very rare for any refunds. Exchanges are not rare however, so you will likely get a refurbished camera body if they elect to replace rather than repair your camera. Their first choice is normally to repair however. Good luck with your repair, let us know how it turned out. Stan St Petersburg Russia