At least for skirmish, Destiny Pickup has made a much better system for finding good matches. But that is more on the community side. Besides that, I guess they have added a few (like 2) maps to each gamemode. Some good balance changes, a few bad (crushthrough), for skrimish at least. Other than that, not that much. Duel and Battle modes are being made, but hard to know when they will be published. Servers are the same. There are some interesting community projects that aim to provide some kind of custom servers.