Your Highness (get it? Like, you know, high-ness?) was directed by David Gordon Green, who worked with Franco and McBride on Pineapple Express and with Deschanel on All the Real Girls. The plot is sort of a standard fantasy thing: A beautiful princess (Deschanel) is kidnapped by Justin Theroux, and two princes—Franco and McBride—head after her. So, I guess, the idea is that you just let Franco and McBride riff.
But, I dunno. It seems like a huge waste of talent to make Franco a straight man. Not to mention the fact that Franco and McBride have two of the best voices in comedy right now, and they're covered up with not-that-great-or-funny fake English accents. And these action comedy movies tend to work better when it's action stars being funny, and not comics being, uh, action-y. Plus, Pineapple Express was, in the end, kind of a letdown, wasn't it? (And, sadly, so is All the Real Girls, once you're a few years out of college.)
But, on the other hand. Fantasy-comedy! Natalie Portman in a thong! There are things I am looking forward to less, for sure.