Ohms on 200, directly together is 00.2 and between TP1 and S1 (I HOPE!!!) is 00.6
OK, that gives you 0.4 Ohms for F3, which is what Gert expects. The latest GPIO +5V values look good -- if anything, they're a little high but within spec, so F3 seems to be working OK. What was the CPU doing when you took these measurements?
Just for fun, I'd check the +3.3V regulator RG2. There should be a pin that's precisely +3.3.V, or you can check C11 which should have precisely +3.3V across it. In the unlikely event that it's not precisely 3.3V, RG2 may be bad or your meter may not be calibrated properly. How hot is RG2 getting? I'm not sure how hot to expect (I don't know when I'm getting my RasPi) but if it gets too hot it will warm up F3 and (if I understand polyfuse behaviour correctly) increase F3's resistance, and then GPIO +5V voltage will start to droop.
Also, there is a schematic of the power supply section at http://www.raspberrypi.org/wp-.....12/psu.png
, which may be helpful.