And I certainly can't say I don't love my iPad - - two cells and all - - but if the 3rd generation iPad (same battery life and screen size) weighs just under a pound, I'm going to go ahead and trade in my current large 24 oz soda for that 15 oz fruit juice without hesitation.
You just made made your original argument pointless.
You first said: "Would you trade 50% of your battery life for 11% of the weight? I would."
Now you're saying, "I would trade 11% of the weight for the same battery life and size." Completely different argument.
Obviously there's a tipping point for weight of the iPad. You said, "why not just double the battery life and weight?" Well, I don't need 20 hours of battery life for watching videos, especially if the iPad weighs roughly 2 lbs at that point. If I wanted to lug around something heavy, I would just go the extra distance and get a heavier MBP or macbook. At least I'd have have higher performance to compensate for the weight.
However, I certainly need more than just 5 hours of battery usage, and that's why I don't think a one battery iPad is sufficient at all. My morning and nightly commutes total roughly anywhere between 2 to 2.5 hours, and I use my iPad frequently throughout the day. I don't want to be stuck with a dead iPad in the middle of the day, and I certainly do not want to be scrambling to find a place to charge it.
That's where the 10 hour iPad comes in. Say I wake up by 8 AM, and I consistenly use it for the entire day, nonstop. By around 6-7 PM, I'd have low battery, but I'd generally be heading home after work around that time, so I can charge it at home.
The current iPad is light enough for it not to be a burden, but powerful enough for me to get stuff done. If an iPad was to lose battery life, it would have to have something much better than "slightly lighter weight" in order to become a selling point.
Roughly 96% of the people in your poll don't think it's worth it to trade a battery in the iPad for 11% of the weight. I'd think that's a pretty strong argument in itself that taking out a battery in the iPad for about 1/10 of the weight, is simply just not worth it.