This Big Battle scenario looks really cool. I am excited to begin playing it. Battle of the Hornburg! 10000 orcs! Thunder and lightning! It makes the skin tingle. 
Player level scaling is a piece of software I have been hoping to see in LotRO for a while now. I even made a post about it listing some potential advantages and disadvantages:

Originally Posted by
dietlbomb
Advantages:
- Dungeons would not need to be scaled individually. Each dungeon could remain at the level it was designed for.
- Players could complete specific zones over a larger level range. E.g. If you've been holding out on the Tomb of Elendil, you can still do it for credit at a later level and there will be more people interested in running it.
- Players of widely varying levels could complete skirmishes and other scaling instances together. 8 level 75 players could earn their seals with 4 level 20s helping out in a Trouble in Tuckborough raid.
- Larger pool of players for lower level dungeons. Most scaling instances are run either at the lowest level or the highest. Players in the 40s don't have much luck finding a group for the Great Barrow, but they would be most welcome in a group of 20s with a down-sidekicking system.
- The challenge of older fun dungeons could still remain pretty high. No 3-manning the Rift. No 20-second Turtle zergs.
- Marks, medallions, and seals could be awarded for every instance at a rate commensurate with each player's real level.
Disadvantages:
- This would require a huge revamp of the game's systems including an open tapping system (which they do seem to be adding in Rohan) and a player stat scaling algorithm. This makes my head hurt.
- Loot dropped in these instances might become more generic, if it has to scale to the individual player.
- Players might not want to go to Angmar at its original difficulty level. We would lose the ability to explore it unmolested.
- Deed grinding would get harder again. Some slayer deeds will require groups. Old instance meta-deeds will become challenging again.
- Mobs in instances would have static abilities. The level 20 wights you fight in the Great Barrow must be defeatable by level 20 players. Challenges for the level 75s would be reduced unless a challenge mode were added.
- Players might avoid certain zones since they can get experience from low-level zones. (i.e. why go to Angmar when you can get experience at level 40 in the North Downs?)
Since that time, we have seen a bunch of the disadvantages disappear. We have open tapping and scaling loot now. If the developers have solved the problem of scaling players' stats and abilities, it may be possible to apply player-scaling to those instances that have so far been impervious to scaling.
As I recall, the biggest obstacle to adding downscaling was that Turbine would be unwilling to devote the resources to a redundant scaling project. But if this new technology is part of the calculus of the Helm's Deep expansion, then it may open the way to scaled versions of Carn Dum or The Rift or The Grand Stair where the original dungeons can remain unmolested.
I do not love the bright sword for its sharpness, nor the arrow for its swiftness, nor the warrior for his glory. I love only that which they defend. ~ Faramir
Undo the U12 class changes. The trait trees were, are, and will always be a bad idea.
Maedhric 105 Captain, Nunion 110 Champion, Taraviel 85 Minstrel, etc...