If you have an Apple device and are using the iCloud Photostream, it is no longer restricted to 1,000 photos. See below for new information.
1) iCloud: My Photo Stream and iCloud Photo Sharing limits –
There is no limit to the number of photos you can upload to My Photo Stream over time, but iCloud limits the number of photos that can be uploaded within a given hour, day, or month to prevent unintended or excessive use.
2) My Photo Stream upload limits –
The My Photo Stream limits below are established based on anticipated upload patterns. Currently, My Photo Stream upload limits are as follows:
Uploads to My Photo Stream per hour: 1000 photos
Uploads to My Photo Stream per day: 10,000 photos
Uploads to My Photo Stream per month: 25,000 photos
If you exceed one of these limits, your uploads to My Photo Stream will be paused temporarily and you may see a notification message on your device. Your uploads will resume automatically after you no longer exceed one of the limits, such as in the following hour or on the following day.
3) iCloud Photo Sharing limits –
The current iCloud Photo Sharing hourly and daily limits are as follows:
Maximum combined number of photos and videos to share per hour: 1000
Maximum combined number of photos and videos to share per day: 10,000
These sharing limits are separate from the upload limits above. For example, in the same day you could upload 10,000 photos to My Photo Stream and then share those 10,000 photos or 10,000 other photos.
Some additional limits for shared photo stream usage:
Maximum shared streams an owner can share: 100
Maximum shared streams a user can subscribe to: 100
Maximum subscribers per shared stream: 100 (the number of subscribers on each shared stream)
Maximum number of photos per shared stream: 5000
Maximum number of comments per shared stream photo: 200 (a comment can be either a Like or a text entry)
Maximum characters per comment: 200
Maximum number of invites a shared stream owner may send per day: 200
There is no limit to the amount of photos you can upload to My Photo Stream over longer periods (such as several months or years). Photos uploaded to My Photo Stream or shared photo streams are not counted against your iCloud Storage. The photos that you upload to My Photo Stream are stored in iCloud for 30 days to give your devices plenty of time to connect to iCloud and download them.
The following image file types are supported for Photo Stream: JPEG, TIFF, PNG, and RAW.
The following video file types and file formats are supported for iCloud Photo Sharing: MP4 and QuickTime file types, and H.264 and MPEG-4 Video file formats. Videos can be up to 5 minutes in length.
When importing photos to an iPad using the Camera Connection Kit, photos are saved directly to Camera Roll. If Photo Stream is enabled and you are connected to a wireless network, you could potentially reach any of the limits listed above. To avoid this, disable Photo Stream when importing photos to iPad when using the Camera Connection Kit.
When importing large numbers of photos to either iPhoto or Aperture, you could potentially reach any of the limits listed above if you have selected Automatic Upload in the Photo Stream preferences. Both iPhoto and Aperture will pause uploading to Photo Stream when the maximum has been reached. Uploading will automatically restart at the next hour, day, or month, depending on which limit was reached.