Thank you for noticing! I use my phone a lot on the site and I think it's a dramatic improvement. I found myself having to expand the page on my phone in order to click really small buttons, like the shared by button or even the title of a post. I would end up on the wrong page often, unfollowed people often etc. The changes were not my design and I had nothing to do with the implementation but as a user of the site first and foremost, I think they are pretty kick ass. As someone that knows some of the changes to come, I'm pretty excited. Like insom said, let us know if anything is buggy or any potential pain points.
I think we will probably have an open discussion about the plans and get the community's feedback at some point before we dive in headfirst. We're in the very beginning stages of figuring out design / implementation / backend so it's a little premature at this point. I haven't been so excited about something in a while, though.