Mine phone seemed to lose battery bat a fairly consistent rate, regardless of how much or little I used it. It would drain a lot either way. With virtually no use, it would be down to ~50% after ~14 hours if I didn't charge it in the middle of the day. I tried all of the usual suggestions to help it, but it just didn't matter. And, yes, like everyone else, Cell Standby was at the top of the usage list. Of course, that didn't seem to unusual to me for a no-use day. However, it was also at the top even when I used the phone a lot.
So, after root became available, I rooted my phone and then used Titanium Backup Pro to freeze all the bloatware on the phone. That improved performance a bit and seemed to improve battery life a small amount, but nothing that would be dramatically noticeable.
Just last week (I think it was Thursday or Friday), I installed the leaked update from the xda-developers site. It made a definite improvement to the phones idle-time battery usage. I think there were some changes to usage reporting (as some have said due to the way Cell Standby used to report so high), but there is definitely a real, noticeable battery drain improvement. Just yesterday, my phone had been off the charger for 15 hours and it was down to 70% with low use. This is definitely a big enough improvement to consider it something more than a fluke or my imagination.
Of course, the link to that update was removed with extreme prejudice and it appears that the removal was prompted by a not-so-polite request by either Motorola, Verizon or both, so it might be difficult to get a copy of it now.
-SR-