The new additions include heroes from Mists of Pandaria such as Shaohao, Sunwalker Dezco, Taran Zhu and more. In addition, players can now find profiles for heroes that have been featured in Hearthstone's class decks. It's a pretty good addition, particularly for characters like Valeera Sanguinar, who plays a prominent role as the representative rogue deck in Hearthstone, but doesn't really feature all that much in World of Warcraft itself. I was also happy to see both Uther and Rexxar have been added as well.
Although the Characters of Warcraft page is by no means complete just yet, the new batch of updates is pretty reassuring to see. Hopefully it's an indicator that this feature won't be left in the dust, and will continue to be updated and filled out with characters that are both pertinent to the expansions we're currently playing, and those that have were important in expansions past as well. Check out the page for the new additions, and while you're there, don't forget to look for short stories you may have missed along the way.