Bukkit

• Improved cooldown support; for kits you can now give cooldown bypass permissions on a per-kit basis
• Economy support now uses AllPay, which includes auto-detecting your economy system!
• Preserve the order of kit contents
• Various updates for the latest Bukkit builds, including MC1.8 items and mobs
• No more "Bukkit will leak tears" errors!
• Teleport, setspawn, and mobspawn permissions should make a lot more sense now.
• No more .* permissions required (some are still supported for backwards compatibility); note, the meaning of some permissions has changed (for example general.time will give permission to set the time), so I recommend redoing your permissions just in case
• Teleport now preserves your facing direction
• CreatureBox no longer required to get mob spawners of a specific type
• New commands: /op, /deop, /mode (equivalent to built-in /gamemode command), /ban, /pardon, /iteminfo (gives info about the item in your hand)
• Teleport warmup now doubles as a cooldown, in that you can't queue another teleport while in warmup
• You can now get a brand-new map centred at your current location with a specific zoom level! The commanda for this are @@/give map/[email protected]@ through @@/give map/[email protected]@.
• Add the ability to give some people a different MOTD message
• Add option for /heal to restore your hunger
• You can spawn wolves owned by offline players once again!
• /setspawn self will now work across worlds, as will /tele home
• Fixed an error in BookWorm support that only occurred if it wasn't installed
• If you try to execute a command but it is refused due to cooldown conditions, a message is printed informing you of this
• /whoami should work now

This is quite a major release, so there may be some smaller changes that I missed from the changelog. More importantly, permissions have changed a fair bit, so you'll likely want to go over your General permissions again to make sure that you don't have any surprises. For example, general.time formerly only gave access to viewing the time, but it now also lets you set the time; basically it's what general.time.* used to be.