The main "content" change in the last two years is a sizable Thargoid invasion of the bubble, and a major change in the way that it gets represented and fought so that it's less dependent on Frontier setting up every single system and mostly automated in terms of what systems they attack - so at its peak it covered a bit over a thousand systems. This includes a fairly big list of new weapons, equipment and scenarios (including ground ones and battles around stations) and a range of new opponents as well including their first capital ship / space station / whatever that giant thing is (and yes, you can - with sufficient collective firepower - blow it up). The invasion appears to be coming towards its end, but there's still plenty of it left to fight for now, and presumably they'll want to reuse at least some of the features elsewhere later.
Other notable changes / new features:
- SCO (supercruise overdrive) is now available. This basically lets you boost at ridiculous speeds in supercruise, replacing the routine straight-line bits of it with more skill and options, and getting you to your destination much quicker overall
- they've reduced the costs of engineering blueprints (especially Odyssey suit/weapon upgrades) and made various types of materials (especially manufactured) significantly easier to get
- two new ships: the Python 2 (don't be fooled by the name, it's a competitor for the FDL and Mamba in the shield-tank fighter role) and the Type-8 (very high capacity medium freighter)
Coming "soon":
- a third new ship: the Mandalay (appears designed for high-speed travel/exploration)
- a complete rewrite of Powerplay to fix most of the original's really annoying features (and probably introduce some new ones, but at least it's a change). In the usual Frontier way the schedule for this has slipped repeatedly but it might be next month if nothing else needs last-minute fixing on it. From what they've shown so far, the purpose (letting players take part in rivalry between major political figures) is the same - but everything else in terms of how it works mechanically and what rewards you get is significantly different.
- a fourth new ship: no details yet
- another new feature: given how much Powerplay's schedule has slipped, Frontier are probably wise not to start talking about what/when this might be yet; consider it just as a "no, for the more nervous players, Powerplay v2 is not going to be the end of Elite Dangerous development" placeholder for now.
