This is a fascinating discussion! What I would offer is that, like many of you, I think it depends, largely on your company and the eventual audience of your work.
At the extremes, an audience of pure lay consumers wouldn't know the difference between a G7 and any other black P&S. They may know enough to suggest that because you have a 10MP camera that your camera must be better than, say, a professional DSLR with 7MP. But probably not.
On the other extreme, are people like us on these forums. Or worse, the audience is the hypothetical uber-professional photographer who eats photographers like us for breakfast (movie reference, anyone, anyone?).
Does it really matter what these people think. Reaction = no. Reality = yes. Yes for the reasons that others have cited -- you may get "further" with a less or more conspicuous camera depending on your situation. A monster zoom lens on the subway is likely to get you some suspicious stares and a less willing audience, not to mention the attention of would-be thieves. A P&S at a professional shoot is going to be met with unspoken presumptions that you are a mickey mouse snapshootin' wannabe who always puts the horizon in the dead center of a image. Hence, you may not be accorded the respect that you deserve because you really are a good photographer, and the only reason you didn't bring your SLR is because you've loaned it to National Geographic because they want nothing more than to hold your camera for a day.
The reality is neither and what really matters is what comes out of your work, in terms of images and personal reward. The camera is only part of the authority that you project -- professionalism (which is what determines one's authority) is about the whole package.
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Mike M
