Additional Back Accessory Slot and Boss Life Meters.

Additional Back Accessory Slot
Basically splitting the "Back" accessory slot into 2 seperate slots for "Upper Back" and "Lower Back". Considering the fact that certain back accessories COULD be worn together without clipping into each other (at least from what I've seen), coupled with all these wings and the Tails Tails being released recently, Its a shame you'd have to dump whatever you have on for something that wouldn't even take up the same room on your knight's model.
I for one would enjoy being able to wear a set of Valkyrie Wings without having to dump my fluffy tails, and I'm sure there are at least a few knights out there who wouldnt mind the same. This may get a bit iffy with say, side blades or vitakits, but slightly moving their models could fix that. And we've already got multiple slots for the head, so why not?
Because you have more than just that one suit of armor you say? Well yeah theres that... But sometimes theres just that one thing missing that you'd like to stamp on so you can truly swag your way through the Clockworks. Killin' with Style! ...yes yes, and that gigantic sword in your hand...
Boss Life Meters
Think of it as a morale booster. A sort of visual representation of how effecient your teamwork or strategies are, or how powerful your loadout has proven. It could also keep those unlucky teams from burning too much energy on revives against "that Vanaduke they thought was near death", saving them from getting put right back in the ground when they realize they were wrong.
This may seem a bit unnecessary to some, preferring to enforce the always-effective "Kill it to Death!" rule, but there are a lot of us that put more stock into statistics and "knowing the battle" and go on to edit the wiki with that data, which I personally treat like an SK bible. Whether its something intricate and numerical or just a bland colored rectangle that shrinks, some kind of feedback as to how much more we have to hit the giant firey palooka before he facepalms the floor would be nice.

Why have health bars when people will CE revive under the potentially incorrect assumption that the boss is nearly defeated? Not having HP bars just means people CE revive out of ignorance more, which is better for OOO anyway.
Besides, not having HP bars that block your entire screen is one of those unique things SK has compared to most MMORPGs.
~Sev

if we have have boss life metres noobs will be distracted by the life metre and die countless times

Like showing damage counts. It can be turned on/off in options. No offense. But I really like the idea. Best for JK runners and Vanaduke runs.

..."some kind of feedback as to how much more we have to hit the giant firey palooka before he facepalms the floor would be nice." sometimes i laugh at small things like "palooka"

Dissappeared for a bit, coming home from work just to fall right asleep...
Sure, it could have a toggle switch. The damage numbers do right? No reason why not. I wasn't implying it'd be something insanely huge though, and I'd HOPE it wouldnt distract people from the giant block of Welches trying to kill them. Doesn't have to be flashy, just small and simple attached to the HUD, but still Spell has a point, toggle switch works too.
And I try not to think that 3 Rings is so sinister that they'd make bosses that cause people to burn out on CE just to make some extra cash. Thats more of a side benefit, not a goal (Least it should be...). Besides, Its not like seeing Boss HP will stop that, just deter it a little. And they have other means of funding. People still Buy CE for mass crafts, Shadow Keys, to exchange for CR to buy AH items, and maybe other things I don't know about. Not to mention all their Accessory Promotions, which people have definetly gone for.
Accessory Slot: While I haven't bought a single one of these, it means more people spending crowns on them, lower energy prices. What's not to like?
Boss Life Meter: YYYYYYYYYYYYYYYYYYYYYEEEEEEEEEEEEEEEEEEEEEEEEEEEESSSSSSSSSSSSSSSSSSSSSSSS! I have always wanted to know just how close Vana is getting to death, and this'll help put JK minis in perspective for those of us without the Virulent Catalyzer. In all bosses, it'll be effective to measure just how much each round of attacking the boss actually does.