I would suggest anyone interested read the full promobricks post that was linked. Using google translate, I think the highlights are:
"The battery box is the same size as the old railway battery box, in the new box the receiver is integrated." So no longer need to also hide an IR receiver.
"We were particularly pleased that the sets a new remote control included. According to our information, there is also an app from LEGO to control the trains." So there will be a stand alone controller and an app.
"In addition to the remote control, there is also a new engine with a new connector. This should make it clear that the new Power Function parts are not compatible with the old ones." While a bit of a bummer...
"However, there will be a retrofit kit, with the old trains can be converted. Unfortunately, we were unable to find any prices for this. The installation becomes easy, since the dimensions for both parts should be the same." ... you should be able to use your old motors with the new BT-battery if you like. Also note that it sounds like the new battery is the same dimension as the old battery (but your clearance point probably moves from the top of the battery to the end of the battery). The key pinch point will be what to do if you have old batteries and worn out motors or IR receivers. The brickshow.com link from the first post noted, "Original Power Functions accessories will still be available in LEGO stores that carry them" (I think this bit came from an earlier promobricks post, but ???) So it sounds like for a few years you should be able to buy old motors.
My first thought was that with the consolidated BT-battery that they are forcing rechargeable batteries on PF, but looking at the wedo 2.0 line, "The hub requires two AA batteries or the Smarthub Rechargeable Battery, each sold separately." So does this mean we are entering the 3v train era? Assuming the PF2 prices will be similar to the wedo prices, the wedo controller (AA) is $63, the add on LiPo battery is $63 (needs the wedo controller, so it is "additional" rather than "in place of" as we have with the current PF battery), and the wallwart is $27 (but hopefully it is the same as the current PF rechargeable plug). So the power + com prices would be double what the PF are today. The wedo rechargeable battery has the plug port on the end opposite of where the control lines plug in. Since the wedo controller sits on top of the battery this could make it more difficult to permanently build the battery into a MOC. Looking at how they fit together, I suspect the same would be true for the PF2 design. The battery pack description does note that it "provides longer run time than AA batteries, and requires a charge time of approximately three hours." So that sounds like it might simply be the PF battery repackaged.
The promobricks post also confirmed the leaked pictures of the trains and gave the MSRP: passenger train is 130 Euro, freight train is 190 Euro
I don't think lego is trying to squash the third party suppliers, but I think they are more than happy to steal good ideas that have proven to be successful. It makes sense to me that lego is revamping PF after 10 years and it also makes sense that they go to BT communications. In any event, they are not singling out the train folks, we are just on the bloody cutting edge.
My concern is the amount of power that the BT-battery can deliver. Right now we have the V2 receiver and SBrick (among others...) so I'm sure something will come out.
Interestingly though, if the wedo prices stand, it looks like it would be cheaper to buy the current PF rechargeable battery and SBrick than PF2 BT-battery + rechargeable.