We just returned from our 2/17 to 2/22 stay at POR. This was our 5th time staying there, so I can give you the comparison.
They took out the bridge that went over the pool. I thought that was an improvement since it made the whole area more open and it is easier to keep track of (see) your child.
The slide is the same but they added a few "leaks" overhead so that water drips on you in two spots going down the slide. We thought that was a nice addition.
On the island in the main pool area, there are now fountains squirting water out over the pool in 3 (I think) spots. The fountain water is cooler than the pool water -- refreshing on hot days. One fountain comes out of an old sink that has a work boot imbedded near it. It is reminiscent of Big Thunder Mountain Railroad.
They also added a waterfall. You know how one waterfall came off an overhead wooden water diverter? Well, that is still there, but they extended the diverter (I don't know what else to call it) over the island and let the water flow off that into the other side of the pool. There is also an old copper cauldron suspended from that wooden diverter that appears to be falling and is overflowing with water.
Finally, they added an entrance for disabled persons using wheelchairs. (One young man used it while we were there and it appeared to be very helpful and easy to use.)
They were adjusting the temperature of the pool well while we were there. Our first day was quite cool and the pool was like bath water. The remainder of our trip found us in the 70s and 80s and the water was cooled down appropriately.
I'm hopeful this is helpful to you all. Let me know if you have more questions. All in all, the pool was nicely improved.