For me, there are actually two new sets of features, since I haven't played for several months. The prior expansion was called Ascendancy, all of which was new to me in addition to the Prophecy release. I decided to play a familiar character while I got used to the new stuff, so I chose to make a summoner witch. She raises zombies and skeletons and such, generally overwhelming the bad guys with superior numbers rather than directly doing damage herself.
The Prophecy additions show up almost immediately. In each town area is a new NPC who takes special Silver Coin items in exchange for granting you a prophecy. Each prophecy gives you some kind of extra effect to normal gameplay, such as extra monsters showing up in a zone or better effects when you modify an item. The coins show up fairly regularly, so I usually had enough to keep several prophecies active at once.
I found some of the prophecies to be pretty useful in the early going, such as adding extra mods to an item. Always handy to get slightly better items than you'd normally see early on. Others were less impressive, such as one that wanted me to defeat a boss while wearing a certain item. I didn't have that item, so that's pretty much useless. Fortunately you can deal with that scenario by "sealing" the prophecy - for a few coins, the prophecy can be turned into an item that you can store away (or destroy, or trade) like anything else.
Outside of the prophecies, I didn't notice much of a change to the overall gameplay experience through Normal difficulty. Progress felt perhaps slightly faster than I remember, possibly due to extra monsters from prophecies, but not significantly so. I wish it was a bit faster, honestly, because a lot of the most interesting parts of PoE are at the higher levels, both in terms of your character's build and gameplay challenge. There were a few monsters that looked new, but not many, and all the zones and story quests were familiar except for one thing: the Trials of Ascendancy.
The Trials are a set of trap-filled side areas, leading up to a major new zone called the Labyrinth. I stumbled across the first one in the second act, without knowing what it was, but it was fairly easy to figure out. Completing all six of the Trials lets you access the Labyrinth in the third act. I actually waited until I'd gone through the fourth act before coming back to the Labyrinth, which seemed to be a good move since the Labyrinth boss was a big pain even with the advantage of the extra levels I'd gotten in act four.
Completing the Labyrinth gives you access to an Ascendancy class, which is a way to specialize your character. For my witch, I chose the Necromancer, which has benefits for my summoned minions. The Ascendancy classes have some pretty powerful effects, which is all to the good as far as I'm concerned. My prior experience in PoE tells me that things get very difficult in a hurry as you move up through the higher difficulty levels. Some games have a problem with overpowered characters making the content too easy, but PoE has a long way to go before that will be an issue.
The trip through Normal difficulty is the simplest part of the PoE experience, and it went pretty smoothly for me as a returning player. Moving on through the Cruel and Merciless difficulty levels is likely to be tougher, though.
