Funny (well, not funny, but interesting) - I am experiencing the exact opposite. I have the extended battery, and up until this update (and a reload of MobileIron and TouchDown, which may have more to do with it, not sure...) I was ending the day with about 45% of battery on a good day after an overnight charge, "low battery" on a bad day.
My phone has been off the charger for almost 36 hours now, and I'm at about 30% charge.
Here's what I'd try if I were you:
1. Pull the battery AND SIM and leave them out for at least ten minutes. I had a lot of problems immediately after the update (Google Talk Video Chat was wonky and unstable over 3G, battery seemed to be draining really fast, and a few other strange issues). I don't know what it is, but pulling the SIM seems to fix things for me, and I've added it to my automatic "after OS upgrade" checklist. And it's harmless.
2. Go through your most-recently-used apps and check their data usage. Try "clear data" (warning, this nukes all saved data, but for things like Facebook all you need to do is log back in). Go through the stuff you don't use, nuke all of its data, and uninstall it.
3. Look at your battery usage chart (menu / settings / About Phone / Battery / Battery Use) - what is using the battery the most? If your answer is not "Display", then you need to seriously look at what IS using the most battery. In my case, after 36 hours, it's "Display" at 51% followed by WiFi, then Cell Standby, then Maps (I use Google Maps a lot), then Phone Idle.