Of all the character classes in Diablo II, the barbarian is physically the strongest and is the best at hand-to-hand combat. He lacks the ability to use any magic whatsoever, which keeps gameplay nice and simple, the way I like it. But besides his strength and ease of use, the reason why this hulking warrior is probably my favorite character in the game is his ability to wield two weapons at once. The left mouse button controls both his right arm and left arm, while the right button can be mapped for skills he acquires later. It's a little tricky to coordinate between both buttons, but I quickly got used to it.
In lieu of any magic, the barbarian possesses several skills that can be used to complement his hand-to-hand combat. This skill tree is made up of three core components: combat mastery, combat skills, and war cries. My barbarian is only at level 4 right now, but as more levels are gained, more points will be available to assign to each of his three skill sets. Combat mastery grants the barbarian better weapon-wielding ability for a number of hand-to-hand weapons like swords, axes, spears, and maces. While it's a little early to tell, but it seems that he'd benefit the most by assigning points to this particular area first. Combat skills give the barbarian unique melee bonuses, like a bash that hits for more damage points, or a double swing. War cries are the closest thing to magic available to him. When he utters a war cry, the barbarian will let go a scream that affects the surrounding area in different ways. As of now, there's a taunt that lowers your enemies defenses, an alert that raises your party's awareness level, and a frighten that scares away nearby monsters.
While this hasn't been quantified yet, it seems to me that the barbarian regenerates his hit points a little faster than the other character classes, with his mana coming back somewhat slower.
I found the graphics to be a little disappointing. Everything's rendered in 640x480 and the 3D parallax effect isn't as apparent as I originally hoped. After a few minutes behind the screen, however, you'll be so immersed in the game that you'll instantly forget about the visuals. One sticking point is the way the beta is set up to play through Blizzard's Battle.net. Hosting an online game with more than two people quickly becomes frustrating, as lag makes it nearly impossible to move around the map without constantly getting "warped" around the screen. This latency problem doesn't appear when playing by yourself.
This beta should run for a few more weeks. Expect Diablo II to appear on store shelves in late May or early June.