...you will need to be extra diligent in terms of adding new or updated Cydia tweaks and apps. One false move, perhaps installing a tweak which was designed for the iPhone or IOS 3.x, could render your iPad2 in a state which requires a restore. If that happens you will be restoring to 5.1 and saying goodbye to your jailbreak for a while!
The only safeguard some of you might have is if you have saved SHSH Blobs for 4.3.3 and your iPad2 is not a CDMA model then you can downgrade to 4.3.3 and jailbreak that. It is the APTicket security which cannot be overcome on the iPad2 without a bootrom exploit, but 4.x firmware did not have this feature.