Another PTS Update was made today on top of the previous ~223mb update. This one was approximately 40mb. No immediate change to the PTS although the datamined files did contain a whole bunch of what looks to be porticulum preview images.
Possible Porticulum Preview Revamp 1
Possible Porticulum Preview Revamp 2
Possible Porticulum Preview Revamp 3
Some are of existing locations whilst others are clearly 3.0 locations (like Izbithu’s Demise and that giant whirlpool).
Another very possible use for these thumbnails would be as Rift Store ‘Featured’ backgrounds (for the boxes in the right hand column of the Rift Store main page). The size does seem to fit.
It’s interesting to note that Trion seems to have made two updates in a single day so as to include these thumbnails. This might suggest that they want these backgrounds on the Live shards by this week’s hotfix – otherwise these thumbnails could have waited until the next major PTS update.
You can check out the other stuff added in to today’s PTS update/s here.
RiftGrate 
Those look like maybe new load screen images. I recognize each one except the new NT places.
I hope those are indeed loading screen images!! They look really nice and I’m pumped to see ’em in full!