When I worked at Apple, my boss's boss was discussing UI/UX design with Steve Jobs in meeting about the Apple Online Store. Steve commented that contextual menus had become the "dumping ground" for the lazy designer.
After upgrading to OS X 10.8.2, last night, I noticed two things. They weren't new things, but they jumped out at me.
First was that Mac OS X is no longer Mac OS X, it's now just OS X. I had heard something about this rebranding earlier this year, but this was the first time that I actually noticed it. In 2001, when I spoke at WWDC, it was beaten into us that we had to refer to it as Mac OS X.
The second thing - and this one's minor - is that the order of items on Mail's contextual menus could be better arranged - much better arranged.
Specifically, when right clicking on an e-mail account the Erase Deleted Items/Junk Mail should be near the very top. In other words, they should be one of the first choices since they're the most common options selected. Personally, I think the New/Rename/Delete/Export Mailbox options probably don't even belong in this contextual menu since they're so rarely needed.
But, that's just my 2¢. There may be a good reason that I'm overlooking.