Overwatch might very well be in its most stable and balanced state since the game launched. However, there's still plenty of room for improvement.
The latest Overwatch patch had a big impact on the game's meta, most of it positive. A total of nine heroes received balance changes in the last patch, and in the newly announced PTR, three other heroes will be receiving balance changes. Besides this, however, most of the other changes coming to the game are merely cosmetic or are there to improve functionality. If you want to check out the full patch notes or want to find out how you can get involved in the ongoing PTR testing on PC, check out Blizzard's full blog post on the topic.
There really aren't very many changes coming to Overwatch as a whole. Voice lines are being tweaked a bit. For example, Blizzard is increasing the frequency of Reinhardt's "barrier failing" voice line and they are also adding a voice line for every hero in the game for when they get hit by Ana's Nano Boost. Team names can now be edited in custom games, and static cameras are now supported in spectator mode. Also, one general change that mostly impacts the Overwatch pro scene is the addition of a pause feature in custom games.
Hero Balance Changes
First up on the list, Ana. Recently Ana has become a major part of the Overwatch meta, and this is due mostly to the fact that her ultimate charges extremely quickly. On a team of three tanks, she could charge up her ultimate once every team fight if you play her correctly. Blizzard is putting an end to this. Her ultimate cost has been increased by 20%, so this could mean the end for the three support three tank meta currently being used by pro teams.
The other change coming to Ana involves her Biotic Grenade. The radius of the grenade has been increased from three to four meters. This was done simply to allow her to hit multiple targets with the grenade more easily.
Widowmaker is receiving a long-awaited buff. Since Blizzard nerfed her quick-scoping potential and decreased her damage output, Widowmaker has all but disappeared from the meta. This might just be coming to an end with this PTR patch. The time it takes for Widowmaker to scope in has been decreased from 0.5 seconds to 0.3 seconds. While this change may seem minor on paper, only time will tell if it will make much of a difference in practice.
And lastly, Junkrat is receiving a small buff. The time it takes for Junkrat to initiate his RIP-Tire is being decreased. This just means that the time between you initiating the ultimate and actually being able to control the tire has been reduced slightly.
User Interface Changes
Overwatch's Main, Social, and Options menus are being changed aesthetically. However, they still display the same basic information. The only change to content in the menus that Blizzard is making involves removing stats from the career profile that were duplicated for some heroes.
New aiming options have been added for controllers. Here are the details on that taken straight from the blog post:
Dual-Zone mode (New default): The vast majority of the thumbstick's range moves with reduced sensitivity and relatively high acceleration. However, when the thumbstick crosses to the outer 10% of its range, it will move with high sensitivity and relatively low acceleration. This mode will allow for more precise aiming, while still allowing players to turn around quickly.
Exponential Ramp mode (Old default): As the thumbstick moves toward the outside of its range, the sensitivity is ramped up exponentially. The acceleration remains relatively high throughout.
Other than that, the only other changes coming to the Overwatch PTR are a few bug fixes and minor changes I didn't feel were important enough to mention. Again, if you want to see the full list of changes coming with the latest PTR, check out the blog post here. Expect the full update to come out within the next couple of weeks on both PC and console. While almost all of these changes are pretty much guaranteed to come to PC, there may be some differences in the console versions of this patch.