Knowing blizz they'll leave f2p unchanged. L20 cap unlimited trial account for the most popular mmo in the world is pretty amazing all in it's self. No one should ask for or feel they deserve more.
edit:
What we can hope to look forward to is a revamped Belf and Dreanei starting zones, so more quests for Good gear. There's been a lot of complaints on the official forums about how Quel Thalas and Bloodmyst are stuck in time bubbles for the last two expansions. Blizzard will probably elaborate the races stories which means new quest hubs. The zones cap out at L20, so; *crosses fingers*
I think it would be cool if they made ghostlands Level 10-15, and then made you goto the sunwell plateau and have the new blood elf players restart the sunwell, as a base to rebuild all of quel thalas. And also expand the entire empty zone West*** of Ghostlands, which if you look on the old Warcraft maps, is also Quel Thalas territory.
Say what you want about blood/high elves, but they have some of the most interesting lore in the game.