I haven't but this question will get varying answers. No significant upgrade was released in the last month (there was a carrier update made available in the last few days) so any battery life loss can be attributted to anything (more data usage, apps, if you're in a poor signal strength area....how often you've used your phone since owning it which could mean you are in the part of your batteries life span that would show more significant loss....etc). It's really hard to say if it's a problem or just the point where your battery life is. Have you downloaded any new apps? Any app updates occur right around the time you noticed the decrease begin? That could be the issue...at which case you would need to contact the app developer and possibly delete the app if it's causing too much of an issue. You can also try resetting all settings (in the settings menu, go to General/Reset/Reset All Settings) and try deleting and resyncing your apps. There are other things you can attempt to see if it helps (if you have not already). Otherwise, if you have done everything and feel like there is an issue and you are still under the 1 year warranty (or extended warranty if purchased) then you can have it checked under warranty and replaced if needed.
Yes. I went from actively using my phone and the charge lasting over a day to not using it at all and it dies in six hours. This problem happened over night meaning that one night it wasn't a problem and then suddenly I woke up the next day and the phone was dead. If you know what's gone wrong with yours, I think it is similar to mine.