Missions & Complexes

There are epic arcs, both for starters (SoE arc) and 1 epic arc per faction. Those require pimpier ships than usual L4s.

Faction warfare is PvP centered around certain low sec areas (marked as such) where a faction (2 empires vs 2) tries to conquer territory over another. You will be freely killable by the opposing faction even in hi sec, even in Jita, till you leave.

Then they introduced lots of anomalies in 0.0 tied to sov, both military and mining.
They also introduced some more L4 and moved L5s all to low sec. Pirate L4 now give better rewards (they buffed the BPC ships etc).

They introduced wormholes, aka little black holes that warp you in random 0.0 "alike" systems outside the regular map. There are of many kinds (with different bonuses given to stats) and 6 increasingly difficulty called C1-C6 with quite nasty anomalies with AI that is much better than L4 AI. But WHs are beyond PvE, they also give you some potent PI (see below) planets and you can put POSes to live inside. You'll be in 0.0 but without the hassle of the big alliances constantly busting your stuff.

There is PI, a new form of quasi-passive income, where you create mini colonies on planets (each planet category has its own minerals etc), extract resources and then take them off on a ship of yours and then sell or manufacture items requiring those materials.

There's Barbie in space aka Walk in station that should probably be the first thing you saw the first time you logged back in game.

They also overhauled the exploration system some times, changing how probes work and generally making it easier.

Apart this and other changes (new ships, check Noctis out for L4, buffs to Minamatar and more) I don't recall anything else.
I am probably forgetting something big but atm I am too tired to think.

Surprised no one mentioned incursions (AKA Sleepers on crack). Also notable for being the first PvE content that can't be done with just you and one or two alts

edit: damn forums ate half my post. To continue:

Incursions require a well-thought out fleet of ships to complete. Unlike missions (which throw tons of weak rats at you) or Sleepers (which throw fewer, but tougher and smarter rats at you), these new sansha behave closer to PvP opponents, using EWAR, cap warfare, and somewhat more intelligent piloting to overwhelm you. Like sleepers, they also will switch focus to drones. Aside from the rats themselves, Incursions introduce system effects that can ramp the difficulty for the unprepared.

On top of this, there're limitations to the amount of firepower you can bring to incursion sites: each site has a recommended fleet size for completion which affects your rewards; bring too few or too many and you may not even receive a reward, preventing say a 20 man fleet from rolling into a vanguard and nuking it in a few minutes.

So why bother with it? Incursions present some of the most lucrative and efficient PvE content in EvE. A smallish group with good logistics can demolish vanguards like a well-oiled machine. Granted, since efficiency and speed is the name of the game, FC's will be picky about who to take (as an EWAR specialist, unless I show up in a webber loki I usually don't get in a fleet), but if you can get in, it's quick easy-ish isk.