Getting it to charge shouldn't be all that difficult using the USB wall charger. Getting it to charge on the clock/radio probably won't work since it probably will no be supplying enough current to that dock connector. Getting it to play music out through the clock radio speakers should also be relatively simple since he is planning on just running sound out the 3.5mm, I believe, to the dock connector...so it will basically be like plugging your Droid in the AUX port on a car stereo or something...the main issue with that will be that it is probably looking for a line level input and not an amplified input, but it should still work, I think...just might end up frying the internal amp of the clock radio maybe.There's more to it than just the cable. The dock won't recognize the phone software. I feel this is impossible.
So basically, I think the data + and - just hanging there not connected is what is preventing the charge.
Just to throw my 2 cents in, i think you may be going about it wrong. You don't need to figure out how to force an iPod to charge, you need to figure out how to get a dock to let the iPod charge. connecting the data lines to the +5v via a resistor applies to an iPod, not a droid (or any standard USB device).
I think you need to figure out how to get the dock to think an iPod is plugged in. Keep the data lines shorted together and then trick the dock.
Just from looking at the pinout from the OP, the iPod shorts pins 15 and 16 together, just like a dedicated charger shorts the data lines together. I'd try shorting those pins together and see if the dock begins supplying 5v power. if that doesn't work, the iPod may actually communicate with the dock to "ask" it to charge, in which case you're probably out of luck unless you want to create a full-blown iPod dock emulator to bridge between the dock and the droid, and i think thats the route you'd have to take to get a dock to play music from the droid.
No matter what you do, you'll still have to plug 2 cords into the Droid. why don't you use a 3.5mm jack to ipod dock (I haven't seen many without one) and plug the droid into the wall (or better yet Moto Dock so it's standing up). I don't see how it's worth all of this work.