Okay so this isn't really a lore thing, but I know y'all love speculating.
By "who writes" I don't mean from a real-world perspective, 'cause the answer to that's probably "Corvinoobus and friends", but from an in-universe perspective. It's just something that came up after I heard about how they're done in the DRK questline.
See, ordinarily I'd write the journal and item descriptions off as a gameplay/interface matter, but the ones written in 2nd person ("You this, you that") made me wonder, because they sounded like they were putting words in the PC's mouth/thoughts.
Are we (that is, the WoL) thinking the item descriptions and journal entries, or is there some narrator (a wandering minstrel perhaps) following us around?