First off, and this isn't a slam on anyone, just observation, but the phone is relatively new. Within that first few weeks, people immediately talk how short the battery life is on ANY new phone. Then, they'll compare it with the phone they may have just left behind. Remember they have had that phone for a while and it's no longer new.
I use the H*LL out of phone when I first get it putting it through its paces and trying everything out hoping it works like I hope. I get mine tomorrow, and you better believe that after I get all 150+ of my apps installed and all accounts added that I'm going to go full throttle on seeing what it can do. Yes, my battery life WILL indeed suck for this 'break-in' period.
Now, after the honeymoon is over and things get back to relative normality, now it's time to look at those things you guys are mentioning above. Wi-Fi/Bluetooth. Constant syncing of accounts and push email in the background. Screen brightness. Yadda yadda yadda.
Bottom line is this: a true power user knows that a smartphone is going to eat battery life when you do so much on it. Extended batteries and spare batteries are the way to go. If you're a tinkerer, then start changing settings. I recommend:
-automatic screen brightness.
disable automatic syncing of apps and email when possible. I have mine set to check for new emails when I actually go to the application. Even if I'm expecting an email response, I just check my email and allow it to sync vs. immediately pushing the data to me.
-one of the biggest....KNOW YOUR APPS and check the settings individually. Pay attention to which apps use the network and check the settings to see if they pull information in the background. Here's a secret, many of them DO by default. Disable or adjust them.
I did a lot of these things on my current phone (MyTouch 4G) and guess what? I increased my battery life by at least 50%. No joke. With all of the apps I keep on my phone, I learned about apps and what accessed what. Made the changes, and I can now get through almost a full day at Disney, constantly updating Facebook/Twitter and checking into Foursquare. Texting and making some calls. Using the WDW Lines app to check wait times at attractions. I'll go from 8 am until around 7 pm with that kind of heavy usage. No, it's not a whole day, but I'm killing my phone with usage.
Bottom line is that it's a little early to judge battery life, however, you can make a difference in how you use it to free up some juice. After the break in period, give it a shot. Trust me, you'll be surprised.