Actually, I recently saw this vid and thought about updating my unit frames and addons to get something similar.
http://www.youtube.com/watch?v=CfZrjwvZ ... re=related yes, thats a priest, but you'll notice they have a crapton of info rolling around the page and it looks pretty nice for the most part.
I did some research and I decided to start using these addons:
1. Shadowed Unit Frames - seems simpler and does what I need. Pulled my char/targetting/pet bars down to the bottom so everythings close together.
2. Power Auras - because you can config it to visually cue you to events you need to keep track of and it looks damn good.
3. Grid - I just use this for raid frames. Its compact and shows what you need to know in a small area, especially if you're dps.
4. SCT - powerful at organizing what info you really need to see when you attack.
5. Viper Notify - Who here has gotten through to defeating the boss fight of a heroic and realize you've been on viper ever since after the first boss? Sounds funny, but it happens to the best of us. Be prepared!
6. Sexy Cooldown - Set it off to the side for a quick reference to when things like trinkets and specials will be ready.
7. Sexy Map - why? because its sexy... and if you really are tracking something, shouldn't the minimap be closer to your char? At worst, it allows you to customize shape, size and position where you wouldn't have otherwise.
8. Bartender4 - This should have been a no brainer to me from the beginning. Hunters only have 50 quick action bars and need closer to 100

. Unless you're a keybinder. One of these days I'll stop my evil clicking ways and see the light.
9. Simple Buff Bars - Have an odd flashing icon in the top corner of your screen? Not sure what it is? This addon might help. Also seperates buff and debuff bars, so you are able to keep less important information (yeah, we still have wintergrasp) off to the side and more important info (YOU HAVE THE BOMB!!!) front and center.
10. Atlasloot Enhanced - how did I ever live without this? What's this boss drop again? What meta gems need what gem reqs? How cool will I look if I ever farm enough frost badges to score a T10 set? Inquiring minds rolled /need.
I also grabbed Overachiever and a recipes list mod while I was at it and these rock too for the packrat/achiever in me.
Hope this list (at least in part) helps you out.