It's pretty much identical to TS2009, but with somewhat better performance. It also has a feature called "Layers" where you can place objects and textures in sessions, this is great as you can have a winter session where the ground is white and the trees and buildings have winter versions. I even have a route I'm working on where I have a session where there's an MOW crew working on one area so it's not there all the time, just in this particular session.
It's also advertised as having a thing called "SpeedTree". This is kind of a false advertisement as it doesn't actually come with it, it comes with trees made with it. SpeedTree is a very expensive program for making realistic looking trees, the developers at Auran used this program to make a bunch of new trees that come with TS2010. These new trees are very texture-rich, with animation so the leaves and branches are moving in the wind, and they look very realistic. They also use more memory, so I mainly use them close to the tracks or cameras and just use the regular trees and tree splines for the background.
It also comes with some really high-quality example routes that are a lot of fun to play with.
I'm not sure what locomotives it comes with as I didn't install a fresh copy, instead I installed it as an upgrade to my existing TS2009 installation. There's plenty high quality rolling stock on the Download Station anyway.
Trains aren't dangerous, it's lack of common sense that's dangerous.