Hello! Please read this important announcement!
Yes you can now change your Minecraft name.

Here are a few things to note:
1. Not all servers / server features will work for you if you update your name
2. We will not be going out of our way to fix servers / server features that don't work for you if you changed your name
3. Inappropriate names will be banned
4. Impersonating staff names will be banned

SERVER SPECIFIC INFORMATION
Survival - Should work fine on - Not XP Keeper though.
Pixelmon - Claim blocks and balances may not transfer
FTB and Tekkit - don't change it.
PVP - No known issues apart from XP Keeper
Event - Islands and ranks may not transfer
SkyCloud - No known issues