[Update #2]: Dota 2 is getting rid of its Battle Pass and instead focusing on more frequent updates.
[Update]: Dota 2's gigantic Update 7.33 has greatly expanded the map, reworked core mechanics and rebalanced just about everything.
After a few rounds of teasers, Valve has now finally unleashed Dota 2's newest ranged hero - the ghostly gunslinger Muerta. As you would expect from that description alone, Muerta is a carry style hero that's all about shooting enemies in a variety of creative ways, to the point that even her ultimate is all about enhancing her ability to shoot someone in the face. It's a fairly simple yet effective design, so I have no doubt that Muerta will easily fit in among the Dota 2 roster.
As for the actual update itself, I'm a bit surprised to say that there isn't anything major to talk about. The meta heroes like Lina and Nature's Prophet have gotten a couple of nerfs, underplayed heroes like Axe and Clinkz are now slightly stronger, the fairly casual Turbo Mode has received some much-needed improvements, and that's pretty much it. The rest of the changes are just very, very, very small tweaks to most of the roster and items, things like Pudge dealing 5 less damage with his Aghanim's Scepter Rot ability.
You can check out the full list of changes, as well as learn more about Muerta's abilities, over at the Dota 2 website.
To be perfectly honest, this is the most ambivalent I've ever been about a major Dota 2 update. It's not even that the changes are bad, but rather that they are so minute I wouldn't be able to tell a new update has arrived without Muerta running around in every single game. I can only imagine that the update was slightly rushed, because as far as Dota 2 goes, this is a relatively poor showing.
That said, it's not all bad news as Valve has already announced that the much more meaty Patch 7.33 will be launching at some point in late April. In true Valve tradition the details are currently nonexistent, but Patch 7.33 is looking like it's going to be a highly ambitious and gameplay focused update, so hopefully it'll help shake things up a bit more.
Once Valve announces a release date, or the update just suddenly arrives, I'll make sure to let you know. Until then, have fun with Muerta!