Although I want the classic Aqua appearance back, instead of the weird hybrid UI that comes as default in 7, I like the new icon (blends in better in the Dock, doesn't stick out like a big neon glowing sore thumb), so I chose to keep the icon.

Although it preserved the Finder icon(s), AguaT still replaced the icon in the About Box. Minor quibble, since I don't go into the About Box hardly ever, but it should really honor what the user selected as far as old vs new icons.