There's an entry in wikipedia (which doesn't make it fact)
http://en.wikipedia.org/wiki/Canon_EF-S_lens_mount
My understanding is that focal length is focal length irrespective of what the lens is being mounted on, so to say that it is 200mm it is 200mm. The crop factor is to calculate the effect of having a smaller sensor, which in the case of APS-C is 1.5-1.6X. The mount (EF Vs EFS) is just the connector for the lens to the camera body, which is independent of the focal length. It just means that you can connect an EFS and EF lens on the EFS body (backward compatible), but you can't connect an EFS lens on an EF body because it is designed to take into consideration the smaller sensor.
Here's a good picture to show the difference between crop factor and focal length:
http://www.dpreview.com/reviews/canoneos5d/page12.asp
For the OP - crop factor is a fudge number to describe the effective zoom by having a smaller sensor. If you have a look at the dpreview link, the easiest way to explain it is that if you had a 50mm EF lens on your camera, you would see just the smaller image. This is because you the rest of the image pretty much shines on the plastic that houses your sensor. Because of this, you see an effective zooming in which would be equivalent to a 1.5X magnification, so your 50 mm lens now becomes a ~75mm @35mm equivalent lens. However, if you use your EFS lens, you get the exact same thing, only you don't have excess image shining on the plastic that houses your sensor because of the construction of that lens. Because of this, it's cheaper to manufacture these lenses than the EF equivalent. If you were somehow able to mount an EFS lens onto an EF body, you would see a small circular image with a black border. Hope that makes sense.