Lord of the Rings Online has been evolving its in-game store for a while now, and it looks like the next phase of its development has a name: Mithril Coins. These coins are new store-purchased currency that's coming in Update 10 and will be used for a variety of in-game activities.
Basically, the use of Mithril Coins is Turbine's way of streamlining several different smaller store options into a flexible currency. These coins can be used as replacements for revive tomes, stablemaster's writs, daily quest resets, and fast travel to quest NPCs.
There's a helpful FAQ that answers some of the burning questions fans might have about this new currency, so give it a read if you're still confused.