I'm surprised at some of the comments here, I thought Apple made it pretty clear iCloud was less about 'cloud storage' and more about 'cloud syncing'
The point if iCloud is to ensure all your devices, including iOS, Mac and PC devices are all perfectly in sync. All of the time. Not provide online storage so you can access data from your devices anywhere.
Because of this, you won't need cloud storage because all your content will be available on your devices.
There is no need for the Gallery feature because your photos will already be available on your devices. Why view them over the net when it's quicker and easier to view them directly from your device?
Personally, I think this is the safer, better way of approaching 'cloud' services.
I don't care if my photos are available on my devices. I want to share photos and videos with friends and family on the web, wherever they are, and regardless on platform on a nicely designed black ad-free interface with great slideshows and animations. And they built the sharing right into iPhoto, Aperture and iMovie. They even have an iOS app for Gallery and iDisk.