First of all, welcome back. Second of all, this is a good time to ask about new stuff, because Wintersday just started! If you don't remember, it's the GW form of Christmas. With this update, Anet added a few good things. First and foremost, if you disconnect from a mission and relog within 10 minutes, you will be put right back where you were as if you hadn't left. Also, they added a party search function which allows you to find people in whatever town you're in (district doesn't even matter) who are LFG for the same reason you are and instantly group up with them. Also, they've added material storage to store your materials and Anet is going to release holiday hat storage sometime soon, too.
Henchmen are now (somewhat) controllable via the new flag system under the compass. It allows you to position henchmen in strategic places or just get them out of your way in case you need to go solo. With the addition of Nightfall, there are heroes now. Heroes are customizable henchmen that allow you to pick their skills and attributes and weaponry. You can also issue them individual commands that are seperate from the henchmen, and you can also manually decide which skills to use at what time, which is pretty helpful at times. There have been many changes to AI, I'm not sure if you were here when they did this, but monsters now run away when they are hit by AoEs like fire storm and meteor shower. But Anet improved this so they only run if they are below 50% health.
With Factions and Nightfall out there are now a total of 10 professions out there. The 4 new ones are the assassin, the ritualist, the dervish, and the paragon. The assassin is a ninja like profession that is meant for hit and run tactics, they can string together powerful dagger attacks and can "shadow step", which allows them to instantly go somewhere else (its pretty cool). The ritualist summons spirits a little like a ranger would to aid your allies or harm your enemies. There are some very potent spirits in a ritualists arsenal, and they also make decent secondary healers. The dervish is a scythe wielding holy-warrior type that utilizes enchantments and a power scythe to deal damage. They can also assume the form of one of the gods for well over a minute and wreak even more havoc. These effects range from healing you when you use a skill to a lot more armor to enchantment removal. The paragon is a spear wielding general type of profession that focuses more on aiding their allies through chants, shouts, and echos. A paragon is a very good addition to a battle and they are very effective as support characters.
All I know about prices is that there seems to be a little inflation going on right now. For instance, if you look at the price of weapon mods here on GWG and compare them to what people are asking for in-game, the GWG prices are a little low. A lot of the green items from Tyria that used to be worth a lot of money are almost worthless now except for Rago's Flame staff, which is still worth a good deal of money.
Hope this helps, and welcome back!