It's changed shit-loads. Boost-jumping/sliding, wall-running... generally speaking though, the "boots on the ground" gameplay is still very similar.
The biggest thing that makes it feel it's changed somewhat is the change to netcode, the lag-compensation is a little too aggressive these days, so you'll find cases of bullshit more often (people being bullet-sponges, dying after having got into cover, insta-deaths etc).