EMC will not update very soon. It is expected to update in a few weeks or less. When it updates to 1.6, the wastelands worlds will reset.
That is a very broad time frame. lol. "a few weeks or less" I don't think it has been confirmed that wastelands will be reset.
That is because no one has any clue when it will update for sure, I would estimate it to be updated in a few(1-6) weeks time, I do not want to put the standard answer of a few years. http://empireminecraft.com/threads/friendly-reminder-do-not-update.3297/
There is no official time of the update - as AIkar has a lot of work to do on it. But I don't anticipate it taking to much longer. And Wastelands! it has ONLY been 2 months. There is a lot of area on the map that hasn't even been loaded.
I feel like by the time we get updated 1.7 will be out (No offense to Aikar, I know he working hard. Just seems like mojang to be a troll.)
http://www.minecraftwiki.net/wiki/Upcoming_features I've heard the ocean update? Meaning more than squids?
Hrm, that is silly I am ok with it. Since it is so easy to reset. But I hope nobody thinks it NEEDS reset at this point.
From the basic block standard, no, but I was reading the Minecraft Wiki a few months ago and this fact kind of stuck into my head: I can't find it right now, but I will It said that passive mobs will have a greater chance to spawn if the chunk is new (horses). That's the only reason, I think.