When manufacturers say that things will last for so many years, it always make me laugh - is it suddenly going to disintegrate when it reaches a certain age?
It's mainly down to storage. If you're going to have photographs on display, no matter what material they have been printed with or on, they are going to fade. If you keep them according to archival standards (for photographs there are a whole host, such as ISO 14523:1999, BS 5687 (ISO 3897), ISO 5466, ISO 6051, ISO 18902, ISO 18918, BS ISO 10214, BS 5699: 1979) then they will last longer.
Digital preservation is a whole different matter - who knows if jpeg or tiff will still be a useable format in 50 years?!
The main thing is to store them properly and not worry about them too much. Keep an eye on ones kept in storage to make sure no insects or mould are present, but more importantly enjoy them! After all, what is the point in keeping something unless it's going to be looked at or used?