Hope this comes in.
I'd love to see this sort of scripting. There's really only two mods I ever cared about from WoW that I'd love to see here.
One was the inspiration for this whole thread, Auctioneer. When I pick up something in the field I generally have no idea what to sell it for at auction, and other sites find it impossible to collect that sort of information. This makes figuring out a good price almost impossible for a lot of items. More than that, for most people this is a game, not a way of life. It'd be nice to have a more reasonable idea of the realistic value of an item, what people are actually buying it for, than just guess-work or a lot of experience.
The second one has to do with bags. There was one called Bagnon that allowed you to rearrange you bag display a lot and, more importantly, allowed you to treat all your bags as one huge thing so that when you were looking for something it wasn't a pain in the neck trying to remember which bag it's in, you just opened them all at once and saw everything. It also made it easier to rearrange items in packs. One could choose the number of items in a row, the size of the display (I routinely made it smaller), the background. Another thing it did was allow one to see what they had in the bank from a distance, which is mostly a time saver since that way you didn't have to go back to town to find out if you had X or not there, you could just look.
I guess I used couple more a lot as well, Reagent info and Mob info. Reagent Info tells me what something is used for, but LotRO does that already. MobInfo, though, gives a good guess at HP, resistances, and whether or not they run, as well as things they commonly drop. I could live without those, though, since LotRO gives the HP which is mostly what I cared about.
Anyway, if here's hoping that scripting shows up in the next expansion! I'd like to see these sorts of things there.