56 Days and counting since problem first discussed with Apple. No help, just reported to software engineers for investigation. Almost two months ago! So much for Apples' superior products and customer service.
Photo Stream works fine between 2 iPhone 4Ss and one iPad2.
Completely removed iTunes, per tech help instructions, and completely remove iCloud.
Downloaded latest iTunes
Downloaded latest iCloud
Logged in to iCloud on PC
Photo Stream still grayed out on PC iCloud Control Panel. Photo Stream doesn't work on PC, only between iOS devices
iPhone 4S, iOS 5.0.1, iPad2 iOS 5.0.1, Windows 7 x64