1. LFR loot lockouts are awesome, Normal and Heroic would benefit from loot-lockouts also
2. Capability to turn on mechanics at a lower raid level (for LFR, team must be pre-made)
3. Split the Normal/Heroic lockouts -- allows players to try next raid level
I always hated the raid lockout system, the LFR loot lockout is a vast improvement. It eliminates that one guy in the pug that has already ran the dungeon from ruining the experience. If you have never joined a pug group, what happens is that one player has already downed a boss, when the group goes into the dungeon bosses are now missing. It is a waste of time for 10-25 players. It is totally possible for a single player to ruin other players experiences by joining random pugs, that they know they are already locked to. Second part of the LFR lockout system I like, is that you can practice the raid as many times as you like. You will not get loot, but maybe you can help a friend or guildmate.
I see it would be really nice to be able to experience the next raid tier without worrying about failure. The capability to turn on mechanics at a lower level would be awesome. They don't necessarily have to do the damage, mainly just there so that players can learn. Not all people excel at researching boss mechanics, and some do not have the patience to watch amateur videos on how someone else downed a boss.
Already, a player that has been working on LFR can still run LFR, and also progress on Normal. Why not extend this between Normal and Heroic? One might argue, that would allow them to do 3 tiers each week. (as opposed to two) If they are starting Heroics, they really have no need for anything from LFR.