I'm posting here for lack of a better place, please direct me if there's an unlocked "main" MountMe thread.
I'm no programmer, but I hope to have gathered enough information to help you talented guys and girls help me :P ... It seems the function "SitOrStand" is now renamed to "SitStandOrDescendStart" and that it's also protected (WoWWiki link). Trying to manualy hack EzDismount.lua in MountMe will make my character stand when I try to do something that requires standing, but I also get the error message about "MountMe has been blocked from an action only availabel to the Blizzard UI". The problem is likely the same in other addons that automates standing up (reported f.ex. here. Is there any way to call SitStandOrDescendStart in a good, non Blizzard-banstick-attracting way ... pretty please, any nice coder?
Also there's a new speed enhancing trinket introduced in the game, although only available (and usable by) druids... You get the trinket as reward for completing the questchain for the "Swift Flight Form". As most druids who own such a trinket would likely not use a regular mount, and hence not use the Riding Crop (that doesn't do zilch for flight form) when they are in Outland, it would be awesome to have MountMe equip the Charm of Swift Flight when using Flight Form, but the Riding Crop when using a Tiger/Horse/Kodo/what-have-you when you're in the good olde Azeroth.
# showtooltip [flyable] Your flying mount;your land mount
/cast [flyable,nomounted]Your flying mount;[nomounted]Your land mount
/equip [nomounted]Riding Crop;[mounted]Your usual trinket
You could include a [flyable,nomounted]Charm of Swift Flight; before the [nomounted]Riding Crop; as well as a Druid. Assuming flying form returns true for [mounted], if it doesn't you'd probably need a completely different macro.