I hope they remove the battleground achievement from Children's Week, but if that's not going to happen then I hope they do something to encourage us to go roam the entire world again like we did the first time the Lunar Festival or the Midsummer Festival was implemented.
Winter veil - More relevant and interesting things beside a daily of going to kill an easily solo-able or duo-able mob (even in first raid armor of expac)
- For the tree area to zone out between servers in Ironforge to reduce lag and to prevent people from standing on gifts to troll
All - For the items to be somewhat relevant and helpful for the patch the event is in like the cloaks from mid summers were never helpful in MoP...
- For there to be more then a dungeon or a boring daily quest to storm through a small quest chain would be nice or something or a variant of dailys for each holiday
Pandaren being part of the Lunar Festival, and having rewards and quests related to them.
A reworked Heroes day (not for just Uther and Grom) but with all the heroes of the lore... and quest and rewards related to them (maybe some transmog items that will look like the armour of thoes heroes, but make it very rare)
I'd add a new holiday. Either something like April Fool's being celebrated in game or a mother's or father's day. Mother's day could honor the earth mother, Therazane, and other lore figures who have children.
I'd like to see year-specific stuff like pelting leaders with the BB gun from 2009 or whatever not count for any achievement points. Make it a feat of strength or something, but it's annoying to see that I can never get that achievement because I wasn't there for that present. Also, entering.