Below is a list of all the updates done in Marvel Avengers Alliance on 5/31/12. Use this list to quickly reference the game play update that might affect you. Please note that this is a direct copy from the official forum. Please also check out our list of complete Marvel Avengers Alliance guides.
Source: Official Playdom’s Marvel Avengers Alliance forum
Marvel Avengers Alliance Hero Rebalance
Black Widow’s Revenge Tactics no longer provokes counter-attacks when it procs. This fixes problems with infinite loops between two Black Widows using Revenge Tactics.
Human Torch’s Nova Blast damage has been increased
Storm’s Blizzard damage has been increased
Captain America’s Shield Guard ability restored to a 2-round cooldown
Several minor balance tweaks to Mockingbird’s stats
Customized Weapons Tags Update
New “Customized” weapons are available.
Weapons marked as “Customized” set their Power Level based on the Agent’s current level at the time that the weapon is acquired. (Either through purchase or loot drop.)
Target Pistol, The Toolbox, Taste of Thunder and Enchanted Crowbar are now considered “Customized” weapons.
Energy weapons that do beam animations have had their animations improved.
Attacks that ignore defense have had their damage reduced slightly.
Various PvE enemy AI improvements and fixes