New Spec (SV), new Interface:



Important Addons:

• Dominos
• TellMeWhen
• OmniCC (edited)
• UrbinRange
• x-Perl
• Grid
• Recount & Omen
• Chatter
• eePanels
• SexyMap

Weight:
I'm down to about 24 MB atm - recount can eat up your memory pretty fast, but for me as a co-raid-leader it's important to track who is damaging whom etc. Carbonite is activated in this screenshot; during raids i deactivate it to save 7 MB of memory.

Explanation:
There's a 5 Button Bar visible for cooldown- and mana-tracking of top-priority skills. Below i put a 5 button TMW-bar to monitor SS-Uptime, ES-Dot, and various important stuff.

It's the first time in 4 years of ui-customization i moved the Unit-Frames "below" my character - avoiding tunnel vision requires lots of practice.. =)

The only thing of particular interest might be the way I've configured PowerAuras to monitor my shot cooldowns and debuff durations. Each of the little symbols down the center below my character represents a shot or debuff needing to be fired with its cooldown or duration directly below, with a priority of top to bottom. For the debuffs, it's two auras for each one monitored; one to indicate the debuff is missing, and another to display its duration when it's up.

Addons:

Interface
-xperl
-Grid (not pictured)
-Dominos
-Sexymap
-Quartz
-MikScrollingBattleText
-PowerAuras
-Range Display
-OmniCC
-Elkano's Buff Bars
-zHunter

Raid/Instance
-Omen2 (not pictured)
-BigWigs (not pictured)
-Violation (not pictured)
-ora2 (not pictured)
-MobInfo-3
-BigBrother (not pictured)

Social
-FlagRSP2 (not pictured)
-Chatter
-Elephant (not pictured)
-WIM (not pictured)
-HoloFriends (not pictured)

Misc
-Atlas/Atlasloot (not pictured)
-Auctioneer (not pictured)
-ItemRack (not pictured)
-QuestHelper (not pictured)

Bobmarley did a great job in summarizing the problem of how to redesign your UI. There's a lot of information that is available to us via the default UI and various addons, but most of the time it's not important.

Unitframes: I don't care what buffs/debuffs are on my fellow raiders. I can't remove debuffs and I trust them to know if they're missing important buffs, so I don't see any of them. Portraits don't help me and only take up space. Mostly I just care if people are alive or dead, so I have very minimalist unit frames. You can also probably reduce the size of your own bars, as well as your target's bar. It's information you care about, but it's not usually the highest priority.

Bars: I see you have all of your aspect on your bars. The only important ones in a raid are Viper and Dragonhawk. Put them on a macro that switches between them and assign it to a button. Then you can just switch between them during combat as needed. I also see all of your melee abilities and traps there. How often do you use them? Granted, I don't PvP much, but I removed all of my melee abilities and reduced the traps down to the 3 I actually use in a raid (frost, arrow, freezing). During combat, the only pet things I care about are Mend Pet and Kill Command. Macro Kill Command and assign Mend Pet to a button. The rest are special case and can be moved somewhere else.

One of the things I did was install OPie. Aspects, pet spells, traps, and healing/mana pots are all assigned to OPie rings. That gets a lot of stuff out of the way while still making them very accessible.

Getting rid of a bunch of stuff allows you a better view of all that's going on and reduces the amount of information your brain is trying to process so you can focus on what's important.