To do that you would to add a collision mesh to every piece of roiling stock.
And to add to that.... We have a tough enough time contacting content creators regarding simple updates and errors. Imagine if they were required to go back and add collision meshes to their content!
This is one of the disadvantges of having end-user driven content. There are so many different developers/creators, along with so many different versions of the program, that it would be nearly impossible to implement without starting totally from scratch.
Starting from scratch has its advantages in some areas, such as all new content, total program rewrite, etc., but then the community is left without content for a very long time. This is one of the complaints about TS2010. Imagine how much worse it would be if none of the old content worked, period, because the program no longer supported it all, because there was no collision meshes.
Anyway, I agree it would be nice if there was such a thing, but at this time I don't think it's feasable due to financial reasons, and the steep development costs that the company would need to support.
The track jumping issue, seems to be a bit calmer with TS2010. I ran a switch while shuffling cars, and didn't end up with cars skidding all over the place. They realistically went on the ties, and with the derailment clean-up session add-on, my derailed train disappeared in about 10 minutes.
John