I've had a bit of a read of the PTR Raid Finder feedback thread on the official forums. Major recurring themes include "leaders need more control over the raid" and "we need to be able to boot people faster and more easily". I'm also tickled by the idea that the queue has to pop several times over before all 25 people actually accept the invitation. It's like the Dungeon Finder times five. =P
It's of course worth noting that this is the PTR and thus player behaviour is only loosely representative of that of live realms.
I personally feel that more comprehensive Raid Leader control is the best way to go, alongside a greater emphasis on the responsibility of the player taking leadership over the group [and of course, options for usurping this person if they are unfit to lead]. This could be something as simple as a warning that pops up when you tick the Leader option to ask if you are sure you are willing to accept this responsibility, or perhaps even add some kind of moderately difficult "qualifier" task to unlock the ability to lead raids. Any kind of barrier to entry would only have a positive effect on the leadership pool, while simultaneously reinforcing the idea that leading a raid is something players need to take seriously.
At least one forum poster suggested the introduction of a Raid Leadership reputation/experience bar, granting points for each boss kill / raid clear. Fucking brilliant. I'm sure there are tracking features in the game that would easily be able to manage such a thing-- I've heard the devs make a few references over time to the way the Dungeon Finder currently tracks how many people you've kicked / times you've been kicked.
I can easily envisage a Raid Finder system in which the Leader role of a would be selected based on a simple check of whoever in the group the has the most Raid Leader experience [in this case, both senses of the word apply]. Perhaps this system could even incorporate a checkbox at the end of the raid in which each raider would be prompted to rate how satisfied they were with the raid leadership and direction, and maybe even scale XP accordingly.
And all they would have to do is make this status externally visible for players, and suddenly a not-insignificant portion of the player base will actively want to lead Raid Finder raids for the sole purpose of pursuing this alternate character progression.