No, but really the lighting does help out with making the textures look much better.

They've refused to do rotating turrets from day one because having lots of independent moving parts on each of the thousands of ships in game would be too much for your poor processor.

There was supposed to be, but we haven't seen them in the Beta yet.

The shadows, lighting, shadder and particle effect updates are a noticeable improvement over trinity. Its not a quantum leap but its certainly noticeable.

There are some new ships, like a new capitalship for every race, and a new corvette class frigate that acts a bit like a fighter. Also each faction now has two subfactions with different strategies and specializations available to them.

That said, the final list of what it will include is unknown. This interview basically has all the features that were ever promised, but not all of them have appeared in the beta yet. Its not clear if they will be added in a later beta, if they'll be added after release (patch or DLC), or if they've been canceled.

Basically I look at Trinity like the original star wars going HD and bluray.

While there is certainly new content, the factions and the titans. It isn't a major overhaul or entirely new version. Sins 1.5 if you will. Graphics is a lot faster and most certainly look better. Lag is still there, although expect since each player can have over 200 meshes going at once, x10 player that is over 2k meshes, all with 10k vertices. Although there are better engine algorithms do help.

Improved AI (maybe it is slightly better against Starbases and things but overall its not an improvement yet), and I think people wanted a lot more functionality out of multiplayer due to the steam integration. Scenarios are the big one though. Even if they're fairly simple if they do end up included that will be a big feature.

If you want to play "the real Sins game", online multiplayer PvP, then you'll definitely want to pick up Rebellion.  Hopefully hundreds if not over a thousand people will be playing it online at any given time.