Four trailers were released before the show officially came out. One for each of the main character's (and labeled by the color of that character). Red first, which featured kickass action from my favorite character of the four (Ruby). White released next, Weiss showed off her musical talent and her magical capabilities (along with some interesting yet elegant swordplay). I discovered and jumped onboard just before the Black trailer was released. It was the first with actual dialogue, and Blake robs a train (or something like that). Finally, the most epic (and longest) of the trailers was Yellow, featuring Yang and her beast as hell fighting style.
There is something you should realize about watching this show. If you're in it for some amazingly complicated, epic story... well, from what I've seen thus far, you're going to be disappointed. I could be proved wrong. Again, they've only aired the first episode. But the story that they've shown thus far is nothing new. It's good, solid ground to tread on. Lots of people like this kind of story (including me, apparently). But as far as I'm concerned, that's not what RWBY is really about or here for.
It's fun. That's why you should watch it. Watch it for the interesting and cool as fuck action sequences and the fun characters. And the animation. I forgot to mention, the whole thing feels like your watching a damn video game cutscene. It's literally what drew me in when I first saw the Red trailer. I was so intrigued by the animation style that I kept watching. And I'm glad I did. Very glad.
Also, the music must be addressed. It really caught my attention. They've done a fantastic job with the music for this show. And it's all unique, too. There are links to iTunes for all their tracks, and the quality of the music (especially for an indie anime show) is especially good. I won't lie, I grabbed a track or two.
So, if you're interested in almost nonstop kickassery, outlandish but fantastic weaponry, fun and entertaining characters, unique animation style, some pretty top-notch music, and don't mind a standard anime storyline (that could very well become more than that), then check out RWBY. The picture up above is also a link to the first episode. If you haven't, I definitely recommend watching the trailers as well. The trailers are listed on the Rooster Teeth website, or you can click the picture below for a YouTube playlist with the trailers in order. Seriously, people. Check this out.