When I got a Samsung S3, I would take it off the charger at 8:30am, and by 9pm, it was dead. I spend my day running in between meetings, so charging is not always possible. I also take a train to work, so tunnels and extra use then takes a toll. If I'm meeting friends for dinner at 8:30pm, the phone is useless. To help out, I got a 3500mAh extended battery for it, and now the phone drops to about 30% by around 10pm, although with heavy usage, I've had it down to 0% in about 13 hours.
I don't see the new Qualcom chips + LCD 3 being better enough to give me the equivalent of 3500mAh runtime. Plus, the longer I have my phone, the more cool apps I find that drain the battery even more.
I'd love to take the new HTC One, port all my current apps to it, and see how it fares in my typical day.