I would like to see the holiday gear rewards be put at the current lfr level. That would encourage more participation. Like instead of 2012 brewfest having 470 trinkets, it would have had 476 trinkets, and then when brewfest rolled around again in 2013 the trinkets would be 502 (I think it was during tot lfr, if it was soo then 528). People would have still ran t 14 normals for better trinkets so it wouldnt trivialize current content, just a little boost for one item slot while gearing up would be nice.
Also I would like to see the weapon and armor pve rewards spread out to more classes. Rogues get winter veil, hallow's end, and brewfest for weapons, dps plate classes get a helm from hallow's end, enhancement shaman get weapons from brewfest, casters who can use a staff get midsummer