This beta is pretty small, so the biggest addition is the upcoming state, which is already highlighted on the map:

As for the new cargo system — I have checked several trailers and cargoes, and something still is in progress (some cargoes have even smaller load, and
Mooring Buoy is just invisible on a single flatbed

), while some cargoes were really improved: the
Empty Pallets now fill the whole length of 53' trailer, and
Aircraft Engines load is doubled — in 1.54 there are four of them on one 53' instead of two. Some smaller cargoes are arranged more tightly (more
Clamshell Buckets in one load, or two
Reservoir Tanks on 53' instead of just one for all trailers), and there are more attention to axles number — we have 9 thicc
Concrete Tubes for 53' with two axles, and 10 with more.
Another improvement of truck adjustment menu makes it look more intuitive and more convenient for console controller users — as with the reworked main menu, PC users will need to make a little more mouse clicks (I remember how I hated the Navigation>Map sequence instead of just clicking on Map button

).
Switching to
PhysX (oh, I remember a lot of talking about it... in 2011-2012

) must be just one of steps towards the updated truck physics, but I think some part of beta testing will include its adjustment as well as finishing the load system, so I don’t expect the release earlier than two weeks, plus an extra week before the
Missouri DLC.