Okay... tested TF2 again..
It still works!
Here is a link to the sourcecode for an example race (which does nothing other than allow you to switch random skills on death). The example is meant only to allow you to understand how you can implement swappable race skills:
War3Source_0000_SkillsRaceSwapTest_OPT.sp
You'll need to latest engine to take advantage of this new way to "swap skills" feature.
My next task is to create "skill packs" as addons that races can use for "swappable skills".