Android phones, apps and tablets

Android is CPU hungry and CPU will always be the culprit when it comes to battery usage.
I am not sure about the latest Blackberry models but about 5-6 month ago all had under 600-800Mhz CPUs.
I have Android Froyo (2.2) running on ~600Mhz CPU tablet and it's sluggish but the battery life is superb. All of the latest Android phones have over 1Ghz CPUs, some dual-core, including my Nexus S which lasts for a day and a half.
So even when taking screen power usage out of equation Android phones will always be more battery hungry.
Andy is right, Android is not designed with CPU/power usage efficiency in mind, you have a Linux kernel and Java VM on top.
but it is a great open (relatively) platform for easy development of apps which is of a great benefit to end users and to Google and it's also attractive to manufactures so everyone wins.
Google have driven mobile hardware technology to progress immensely in the last two years which again benefits end users. But battery technology is yet to progress.

Eh? Screens use way more power than the CPU.

Blackberry CPUs are low because they don't do anything.

Did you consider that the tablet battery life is better because the battery is much larger than the size of the one in your phone and the phone is out and about trying constantly to maintain a connection to cell towers whereas your tablet is probably in your lap for 10min whilst youporn serves up the freshest of fresh?

Android and the underlying linux kernel have power management facilities in place. Andy might be right in saying it's not the most optimised (it wasn't designed and built ground up for mobile) but to say "Android is not designed with CPU/power usage efficiency in mind" is bollocks.