Instead of adding new heroes, Icefrog been releasing new items. While not as flashy as a new hero with new funny lines and abilities, I think this shake up the gameplay more.
I think the Blademail change may have the biggest impact. No more popping Black King Bar and going yolo. I think this will separate great carries who know how to control agression from yolo carries who just popped bkb and went nuts.
The spell damage I mentioned is nifty but don't expect spells to one shoot people like a farmed carry, would Still extra damage is extra damage and it helps you feel a bit more powerful come late game.
Overall, I'm curious to see how the top teams will adapt to the changes. Good job Frog of Ice. Now stop nerfing Death Waifu so I can play her...