Your iCloud Photo Stream can sync to iPhoto and Aperture on a Mac, or the Pictures folder on a PC. You just have to enable it in the app preferences, iPhoto, Aperture, or iCloud Control Panel for Windows.
See this for more info -> iCloud: Photo Stream FAQ
iCloud pushes all your photos to the My Photo Stream album on your devices and computers, and manages them efficiently, so you don’t run out of storage space.
Your iOS devices keep a rolling collection of your last 1000 photos in the My Photo Stream album. From there, you can browse your recent photos or move the ones you like to your Camera Roll or another album to keep them on your device forever.
Since your Mac and PC have more storage than your iOS devices, you can choose to have all of your My Photo Stream photos automatically downloaded. In iPhoto or Aperture preferences on your Mac, be sure to select Photo Stream > My Photo Stream > Automatic Import. All of your photo stream photos will be imported into your Events, Projects, Photos, Faces, and Places folders in iPhoto or Aperture. On your PC with Photo Stream enabled in the Control Panel, all of your photos will be imported into C:\Users\<user name>\Pictures\Photo Stream\My Photo Stream.
Ok now I have same question. I have photos sitting in the icloud. It tells me all the time my iCloud storage is full. Got my new iphone activated and there are no photos pulled in the photos under camera roll or photostream. When I go into photostream it even says it will pull it in automatically....and nothing,