The waybill number is *not* going to give you any info about the cargo flight - the DHL tracking link and waybill number is only for the final carrier, DHL Europe. It's not for the DHL Air Cargo flight. Those begin with 7CPXXXX, and Apple will not give it to you (some CS reps did give them to the 2-3 week'ers, which is how I was able to piece all this together, but they weren't supposed to, and now they get in trouble if they give it to you, so they won't).
Basically if you're freaking out, don't! The chances of Apple "losing" your package are slim to none. If you have a tracking number, sit back and relax for ~72 hours. Your Mac will most likely have reached Amsterdam by then.