A rather unusual example. Uhura in the 2009 film is played by Zoe Saldana, but in comic 7, she's seen reading an Ebony magazine with the original actress, Nichelle Nichols, on the cover.
The same kind of example in Sulu's case. After George Takei came out of the closet, some fans assumed his character was also gay. Word of God has denied this claim, but that hasn't made certain artists rule out the possibility entirely...
Ensign Two features an appearance by Sherlock Holmes—specifically, the 21st century version of the character from Sherlock, played by Benedict Cumberbatch. He helps them figure out how to stop the Sues and leaves, but not before sinisterly predicting that he and Kirk will meet again. This alludes to Cumberbatch playing John Harrison/Khan in Star Trek Into Darkness. However, it was recently revealed that "Sherlock" was actually Khan impersonating him by using their likeliness after kidnapping the real Sherlock Holmes, and that the plan to stop the Sues was really a ploy to bring them in one dimension.