SB Nation has been slowly rolling out new commenting code across the network, and it will finally be implemented in full today. Nothing will change in the overall functionality of comments, but the system will now use a more modern and robust javascript language. Essentially, the comments section will simply be faster.
Most importantly, you will now be able to navigate the comments on any mobile device in a similar way to what you can do on a PC. Yes, the 'z'-button is coming to your phone.