Many people were able to enjoy the beta of Torchlight II recently, but alas Runic Games had to shut down those servers to make final preparations on the full game. Feedback provided by the beta testers has caused Runic to tweak certain aspects of Torchlight II, like the skill trees. In the beta, the skill trees functioned like prior action RPGs with invested points bumping up the damage done or critical hit chance. Now, Runic is changing the skill trees to provide for more interesting rewards at higher levels, like powering up the Embermage's electrical attack to grow deadlier and chain between targets. Other classes will be receiving similar tweaks, and hopefully Dexterity will be changed to calculate ranged damage as well. You will be able to see these kinds of changes on the screen too, instead of behind the scenes.
One other thing Runic is changing is toning down the magic effects and altering the targeting system. Now when you are journeying with your friends you will be able to keep an eye on everything going down and have an easier time picking an enemy to kill. This should keep everything from being overly hectic during large battles.
Runic is aiming for an end of summer release for Torchlight II, but did not say a specific time. Once the PC version does ship we can expect a mod editor soon after and even the Mac version. Torchlight II is available to pre-order right now on Steam for $20 (or a four-pack for $60).