Well I'm part of a small law firm (4 partners, which I'm one of) and we have a total staff of 15 right now (paralegals, admin, interns etc)...I like to think that our employee handbook is well written and fair (since that's the type of practice we have and because I wrote parts of it!), we have no policy against "weapons" specifically, but there is a general "employee personal conduct" section that basically says that your expected to act professionally, ethically, within the law and so on.
I have a CHL, as does one of my partners, and we both routinely carry in the office. I do not know if any employees do, and I really don't care, I'm certainly not going to post a 30.06 sign on the door ever. I usually dress fairly casually (since I very rarely go to court) and often wear nice jeans or chinos and usually clip a knife on my pocket. It has never really been a topic of conversation except a few rare times, and never in a negative way. An amusing moment was a few months ago when I bought my first auto and had it shipped to me at work, I had just unboxed it in my office and a then intern came in to bring me some documents and asked me about it. I explained the change in the law as of last year (had to make it a "teaching moment" after all) and let him fire it a few times. His reply was that it was "sick!"...I think that's a good thing right?