It is just the older needles, so I'd not be too worried at the moment. Equally, "Nothing has changed in regards to watering or care" - yes it has; temperatures are dropping at this time of year, so evaporation is less; the same amount of water sits around for longer, so maybe you are over-watering now.

Resin

ALL interior browning is normal ...

ALL conifers eventually shed their needles ... normally 1 to 3 years on the plant ...

the shedding varies year to year.... sometimes very noticeable.. sometimes barely any ...

it is increased by drought ... and in your case.. transplant ...

the only key .. is that the buds look OK ... you only have a problem.. when they blacken or get mushy .... and by that time.. you will notice the exterior browning ...

keep it properly water late into the fall ... and all next summer.. and you should be all set...

i would NOT waste another minute worrying about it..

ken

I cannot see your pictures, but this time of year, some needles will drop. Although they are called evergreen, they still normally shed some needles in the fall.
You might want to see my post on our Norway Spruces to see a Norway that was severely damaged, now dying due to lawn chemicals (Ortho WeedBGon). Out of 3, two of them have had no further damage, but one is probably lost. It is still just barely alive and the damage has stopped progressing, but I doubt it will ever look good again. The top third is completely brown now.
Spruceman was a tremendous help at the time, to recommend watering well, which saved 2 of the trees. Although the lawn chemicals were applied correctly, we had no rain for too long afterward; the chemicals killed large areas of lawn as well. The lawn was reseeded and has since recovered. The Norway will not.
My point is, avoid lawn chemicals around your Norways...

Here is a link that might be useful: http://forums.gardenweb.com/forums/load/conif/msg090824531551.html

We have a large three story high Norway Spruce in our front yard. This year large clumps of the branches are dropping off (about six inches in length). They are not brown. I've been told everything from squirrels are eating it to the tree is just old. I'm very frustrated.