I love this update, all the new stuff is awesome, but I was hoping for more new dispenser abilites than we got. Stuff that fit right in with all these redstone additions, like the way they made it so that dispensers can use bonemeal on plants in front of them.
I also wanted them to be able to plant plants, and breed animals, in order to make fully automated farms and ranches. Bone-meal usage was on my "wish list" for redstone stuff, but the update was lacking these dispenser abilities. Most of the updates for 1.5 were on my "wish list," which makes this an amazing update in my opinion.
I was also hoping that they'd add a block that when powered by a redstone pulse turns whatever item that is in front of the business end of the block into an item. I call it an "itemizer." That'd really help for auto-harvesting cobblestone generators, auto-harvesting farms, and even it'd be useful for automated mining.