Let me start off by saying that definitely is not a bad thing.
Some of the enemies remind me of the Space Pirates, especially their color. Steel and gray with Orange highlights and monstrous features, and even some of the weaponry, like that orange plasma "sword" used against Chief in the Campaign video. Not to mention, the lush green Forerunner world reminds me of Tallon IV from Metroid Prime.
I also heard some element's of Metroid Prime's score while listening to the score from Halo 4 in one video.
Even Visor elements seem more Metroid.
If anyone from 343 reads this, I want to ask:
Did you take elements from Metroid thinking "Hey, I really like this, let's see how it feels" ?
Metroid Prime is easily my favorite single player video game ever. It felt often solemn, yet adventurous and fun at the same time.