i think the most important improvement is the new Search feature. Now you can put filters into your search request for things like hulls that have so many slots or made by a particular race or less than a certain cost. You can search for specific trade goods etc. Makes it much easier to find what you are looking for instead of the old search (which is still there in case you want it). Also, I don't think this was in the original, but now you can have 3 different configs for your ship. So you might have some weapons setup for one situation and different weapons setup for a different situation. On the Ship inventory screen at the top you can click 1,2,3 to quickly switch between your configurations.
Oh, and speaking of the ship screen, you can click a button to expand the cargo hold display so instead of only seeing like 5 items and having to scroll you get this real big window with something like 6x20 squares and some auto-sort buttons to make it easier to dig through your cargo for what you are looking for.
Those options were enough for me

I think you can now sell your micromodules for nodes which I think is a new feature.
Just make sure you download Netriak's modified exe he posted in one of these threads. It fixes a couple of bugs with the new search window and some crashes related to the new high-end unique ships that are available.