Well, the good news is that most iPhone and iPad users probably don’t take 1,000 pictures and keep them up on their device. Perhaps you do, but we tend to back up some of the older stuff and put it on our computer and in our Dropbox (how to load iOS device images onto Dropbox).
Still, if you allow those photos to accumulate, you will quickly reach 1,000 or so. Those photos (unless you have things set to do otherwise) will also sync to PhotoStream, even if only for a set amount of time, and we’ve learned that PhotoStream will only sync up to 1,000 pictures. New photos will show up, but old ones way up the stream will be replaced as you take more and more photos.