Solo play is harder now then ever. Before a soloer could go at a lair and just use area attack to kill all the creatures around them and the lair. Now picking them off one at a time is more favorable. Grouping has changed dramatically. In fact, the new changes encourage grouping. You now get the appropriate XP and reward payout.
The environment has changed a little. Static objects are now viewable much much further then before. Coming over a hill and seeing Coronet or Theed still 2km away is quite the site.
Even starting out a new character is a lot better then before. For a while now they were giving out "speeder rentals" to new characters which allowed you to have three rents of a speeder. Now they have a slower/weaker version of the X34, the X33 that they give you.
The GCW has really heated up. Major NPC's like Darth Vader and Mon Mothma make semi-regular trips to major cities to encourage participation in the GCW. There is a new system of planetary control. Factions can take over other faction controled NPC cities. You can keep track of the latest news in the GCW via News Terminals.
A lot of new weapons have also been added to the game along with an entirely revamped looting system which adds more diversity to the Galaxy Economy.
Actually, that's not true. A lot of the new revamps are based off of how the game was originally designed. In Beta everyone had enough Med skills at character creation to use Stim A's. Due to Medic and Doctor complaints, they took this out before Release. Now you can use Meds again (though with less effectivness then doctors). BTW, Combat Medics can Rez now also. All healing (including Rezing) by Medical Professions are now abilities (no meds required). All medical crafting has now gone to the Bio-Engineer profession.
Entertainers,
I don't know where you last dropped off with entertainers but they have learned tons of new flourishes, dances, and songs. The skill points have also changed so that it is now possible to master Dancer, Musician, and Image Designer. Droid Engineers have entertainment modules they can install on droids to help provide a neat little side show for entertainers. Since the Jedi grind was taken out, you no longer see masses of entertainers macroing. It's back to the dedicated social players (tips welcomed).
There is a scheduled revamp of the entertainers and crafting professions to come next (Smugglers included, though they've already recieved some changes).
I strongly urge anyone intrested to visit the main site (starwarsgalaxies.com) and checkout all the new changes since the last time you played.