I'm not the best person to ask. I've recently decided to collect as many different Disney international collectors DVDs as I can.

I've the French, UK (and US on order).
However, no it's probably not worth buying the R1 if you already have one of the current 2 disc international releases. But the lack of trailers does annoy me - there's no reason for it (the French 2 disc "Peter Pan" has no trailers either).
The existing releases seem to have a flawed transfer, with colour shimmering. While its an unknown quantity at this time, I suspect the R1 will also suffer from this fault, but perhaps not. One possible reason to go for R1.
Also anyone waiting would probably be better waiting for R1 as it will include the trailers. The DTS sound is not really an issue for me (it's an old film and I have no amp, let alone a DTS compatible one).
Personally while not a big "PAL - NTSC" advocate, I do feel that the additional definition of a PAL transfer is more than noticable with animation (while I feel its almost undetectable with most live action films on my medium spec television). That's why I decided to buy the French "Roger Rabbit" in addition to my R1 set. So ultimately the R2 PAL version may have the better picture and 98% of the supplements.
The choice is yours, but if this release isn't going to be a Platinum branded release (the new cover would seem to indicate that) it's probably worth waiting, as any future R1 Platinum release may have even more supplements added!