It's been a long time coming, but with the introduction of Ice Cream Sandwich, Android finally takes a significant leap forward in terms of camera and gallery features. The camera interface is completely new -- it's faster and easier to use with instant access from the lock screen. Shots are taken immediately thanks to zero shutter lag and continuous autofocus with automatic face detection. Touch-to-focus with exposure lock is now supported, and the UI adds a proper digital zoom slider. The camera app also includes a new sweep panorama feature.
The gallery app is also significantly improved, with Instagram-like "hipster filters" and a built-in photo editor that lets you crop and rotate pictures at arbitrary angles. Any tweaks you make are saved in a separate file, keeping the original shot intact. Images can now be sorted by location (using geotagging), and by person (if manually tagged). Video also receives a serious boost in functionality with 1080p capture, continuous autofocus, and the ability to zoom while recording. Additionally, it's now possible to create time lapse videos right from your phone.
It's too early to tell if all these features will trickle down to legacy devices or remain exclusive to the Galaxy Nexus, but we'll find out soon enough.