No, I don't work on YouTube, but there are at least a few dozen Googler bronies.
Other MLP easter eggs: if you YouTube search a pony's name, it changes the color scheme to match. And if you use Google Hangouts text chat, there are fun ones there, too, including /ponies to make a pixel pony (like these on YouTube) run across the window, and /ponystream to make a non-stop parade of them run across.
I work on the display ad trafficking tool that advertisers use. But even on that "serious" product, our team has been kicking around the idea of easter eggs. Far fewer people would see it than one in YouTube or hangouts, but we'll see what we can do. :)