Resolution of iPhone photo stream upload! I've not been able to pin down whether the photos uploaded from an iPhone to photo stream are full resolution. I saw mention that they are downloaded in full resolution to OSX machines and not iOS. But not how they have been uploaded.
Yes, I can confirm to you they are exact the same.
Photo's are exact the same format and file-size.

You can also verify this yourself by connecting your iPhone to your PC using the USB cable and get one picture from it. Check the size, resolution and format.
Now open your Photostream and do exact the same.