LFG and every kind of raid forming addon I've seen all work the exact same way. A raid leader makes a raid, post it and then waits as it sits there surrounded by many other raids that raiders have to sort through and queue up for. A lot of times the comments in these such as "Need ranged dps/mage/rogue" or whatever are ignored and you have class after unneeded class queuing up wasting everyone's times.
Even Open Raid works like this with raids listed... the raider signs up... then he has to wait in hopes of getting selected. Many people don't even bother as they dont feel like sorting through all of the raids and then signing up to wait in hopes of being accepted.
Why doesn't this stuff work in reverse?
If a raider wants to raid Normal HFC he simply opens the addon, puts a checkmark in the box for Normal HCF. He can add two things before submitting. 1) minimum Raid item level (Averaged) and a comment. The addon then snapshots that characters spec/stance(if prot warrior),worn item level, and current raid progress/lockouts. The raider is then free to go on his way questing or whatever.
The raidleader, while having his group listed in hopes of getting what he needs, can open the addon, put checkmarks in the boxes for the raid he is in (Or the addon could detect it automatically if he was in the instance) then he could checkmark what he is looking for. For example:
Say he is looking for a tank. Well he would put a checkmark in the "tank" box, enter minimum item level and hit submit.
This would bring up a window of all characters for his faction that meet his criteria.
Now lets say he NEEDS a DK tank. Well after he hit the "Tank" checkmark it would populate a class set of boxes that can be checked.
This just seems so much easier than what we currently have. Why do we have 2000 (imaginary number) sitting around looking for 1 of 200 raids (Whom are probably just sitting around also) instead of an easy system that would allow those 2000 people to do other things while raids slowly form.