Unfortunately , the script files are encrypted, so there is no way to upgrade them to 2010. However the Hump Tower and the version 1 retarders will work in 2010. The version 2 retarders were for use with the Database Controller, which allowed cars to be routed automatically (the cars could have predetermined assigned tracks) and they will not work in 2010. So, basically it will still work, just without the Database option, which I'll admit was pretty cool.
I found it better, if you don't even download the version 2 retarders. A few times having both installed seemed to screw up the version 1 retarders. Probably just a quirk, but as they don't work, I wouldn't even bother with them.
Fitz