Was there any significance to Wil Wheaton being in the theater to watch Star Wars with Koothrapali, Leonard, and Howard, while wearing a Star Fleet uniform in The Big Bang Theory episode "The Opening Night Excitation"?
The plot and dialog from the episode answer this. Wil Wheaton is a troll, and enjoys messing with people (remember the bowling games?). And he's most known for playing Wesley on Star Trek TNG. The Trekkie vs Jedi (Star Trek vs Star Wars fans) feud is as famous as the Hatfields and McCoys (No, not that McCoy.)
At the movies, the audience starts booing since Wil Wheaton shows up in a Star Trek uniform dressed as Mr. Spock. Wil is loving the rejection. He tells the guys that since he was on Star Trek he's rooting for the home team. Someone calls out that Star Trek stinks. Wil replies, "Live long and suck it."
From the transcript:
Oh, did you hear from Wil?
Yeah, he's on his way. Time for bladder check.
Check. Wait. Screw it. I'm holding it.
What is everyone booing at?
Wheaton: Hey, guys. What's up?
Um, hey, Wil. What you doing?
Wheaton: I was on Star Trek. I'm just rooting for the home team.
Man: Star Trek stinks!
Wheaton: Yeah? Live long and suck it!
Someone should have told him to "Shut Up, Wesley", that really pisses him off (in real life):
Wil Wheaton played Wesley Crusher on Star Trek: The Next Generation.
It's a simple joke that despite seeing Star Wars, he's wearing his Star Trek uniform instead.