Hi, the limit per slideshow is 1000 slides (photos). But if you are creating something like a DVD, then you could have more than one slideshow in your DVD project. A DVD will fit about a 1000 slides . This would take on average (7.5 seconds per slide) just over 2 hours to watch.
For 2000 photos you may want to split it up, but depends what you are trying to create?