The patch appears to have reduced the amount of crosstalk (2 voices maximum), to the point where you can actually miss out on voiced dialogue from your party (it will only appear as text instead) if two nearby NPCs are making a comment. An annoying drawback to the fix. In the end there is less chatter happening at any given moment.
Busy places like the docks and the marketplace are always going to be, well, busy. They're packed with NPCs working and hawking their wares, and shouldn't be expected to have the ambiance of a library.
If you were expecting the cheese vendor not to talk about his cheeses anymore, you're going to be disappointed. He has a variety of comments he makes and the same one usually isn't repeated for at least one minute. That is more than reasonable.
If you find it overwhelming, I suggest tweaking your voice volume in the audio options. You should set it so the voice at your camera's location (usually centered on your character) is at a pleasant, normal level. Voice volume is scaled with distance, so if you take the time to do your settings properly you can get the banter in the background to sound more like, well.. background noise that should be easy to tune out. Again, the volume is loudest where your camera is focused, so if you're moving your camera independently of your character and over nearby NPCs who were chatting, expect them to be louder.
The chat box always picks up the dialogue of nearby NPCs. You can stop it from moving and focus on a single point in the dialogue by simply rolling it back from the latest entry. It will not automatically move again until you either move it yourself, or return it to the latest entry manually.