The latest changes I can't say much of, but soloing is a valid option in the game now. Just about everyone can get from 1 to 90 on their own, ofcourse you have to accept that there is content you will not see or only greyed out if you do not group, that's only natural. And things slow down a bit at some levels, although SOE tried to remedy that too.
EQII from the release and the EQII today are almost completely different, no more starting on one island, no more doing quests to get your class at 20, a lot of ways to travel (boats, spires, rings, bells, spells, ...), huge amounts of quests and zones.
With the latest GU, there's a new beginner's zone, might be a good idea to start at Halas, you should find a lot of people there checking everything out.
And welcome back!