Don't let the non user replaceable batteries scare you. Google and u can easily find guides on how to replace the battery if the need arise. But i believe the battery life would be enough for most users.
I have been taking snaps with the 12 mp camera and the xenon flash is fairly handy in low light conditions. Can it replace ur normal digital camera? Perhaps. I've seen some beautiful pics being taken with the N8, in fact they ran a competition or something on it. So it is definitely a contender for one of the best camera u can find on a phone.
The N8 also takes excellent videos. All in glorious HD. And the HDMI output makes it easier for you to share your videos on a big screen. Which reminds me i should probably try that out too. Transferred a rip dvd of Inception onto the phone at it plays smoothly enough. But i guess that's down to how u encode ur video right? The phone is truly a multimedia powerhouse.
For more sample pictures u can click here.