You may have seen the latest part of the Heavy Update: Arena Mode. I'm going to give it a chance, but my initial reaction is negative. The last thing that I want to see is Team Fortress: Counter Strike, and I have a feeling that that's what this will dissolve into, especially in random public games.
One thing I do like: With a more open, less structured map, with only one key point that isn't necessarily important, scouts will have a chance to really shine.
They've also revealed an alpine environment. Not too exciting for me. I'm going to give that a chance too, though.