Marelli
As for not wanting to level skills from 250 to 300 again...
I think it's a lot to do with how the game is at the moment, that you don't count in endgame content unless you're max level. Invasion events now are often full of level 250 or higher mobs, and anyone not 250 at OP battles is just launcher fodder.
I'd say this has more to do with how few players Ryzom has, than whether or not the level cap gets raised.
Without new players, of course everyone hits the cap.
The last OP war I was in, I showed up too late to stop our side from losing, but early enough to run around with a ~190 in 2h axe and kill a much larger number of healers than someone over 50 levels below the cap should be able to, if everyone was truly 250 at the OPs. Blame my lack of squishiness on the addition of Ryzom to the Mac App Store, and continue to push for new ways to advertise the game.
Increasing the level cap allows high end players to once again be differentiated by more than their equipment, but diversity still comes from the size of your player base. As far as people not wanting to level the extra 50 levels, to me that just sounds like people who don't enjoy the game but want to hold on to their elitist attitudes. Maybe MMOs aren't the right fit for them? Sorry if it sounds harsh, but I agree with Loryen about playing the game for fun and levelling as a byproduct.
What I would like to see most is new regions of Atys that are currently hinted at or blocked off, like deeper into Kitin's Lair. Whether or not the level cap needs to be raised should ultimately depend on the difficulty of the creatures that inhabit those areas.