I often shoot in less-than-ideal weather conditions. Last winter, I froze my Leica M3 almost every day, and my fingers along with it

. The same for my D3 X2. And the Leica M7 near the end of the winter.
When it's really wet, like snow that melts, I use plastic bags and I even bought a Sport Shield. Not cheap but very cool.
Last winter I was in some of the worst snowstorms of my life and I was glad to have the Sport Shield.
I'm sure soaking a Nikkor 300 2.0 IF-ED AIS wouldn't do it much harm but I really don't see the point if I can help it.
I'm thinking of getting a couple for the MP/ M7 this winter as I'm going to be shooting while skiing with the Leica M. And they're going to get sprayed as I'm going to be using the 12 mm ASPH up close and personal.
And as a bonus, they put a layer between your skin and the metal which is very nice if - like me - you like to shoot with bare hands.
For me, fogging up is by far a bigger problem ... going out into the cold, back into a warm car, then out into the cold, then back again.
Bagging is the only option or keeping the car cold.
Which is not going to happen. I only come in to change locations and warm up

. It gets cold here.
When I finally do come in from the cold, I plastic bag all my gear. It's a pain in the ass, but I do it.
Sorry, my examples are not as sexy as Frank's unless you're a cow. Then this bull might be pretty sexy

.
Nikkor 300 2.0 IF-ED AIS on D3 with Sport Shield hand held.
I don't think getting most cameras a little wet now and again is bad. It's if you're doing it every day, like I intend to, that you could run into problems.