I have read easily 50 threads on injector failures before and after purchasing my 2003 LB7 duramax. It does seem that the common failure is either a sticking injector or cracked housing. Many have eluded to the fact that poor fuel quality can and will add water to your fuel system and also additional particles that might make it past your stock filter (esp if you have the first gen filter with larger micron filter media).
I have decided to go the route of adding an external, in-line, 2micron prefilter (Cat type) for additional particle filtration and water removal. Since my injectors and fuel system were recently flushed by the dealer before I purchased the truck, I'm starting at a "clean" baseline. I also saw in the history of the truck that the first injector(s) were replaced somewhere around 30,000mi so I also am on my second set of injectors already.
Adding another prefilter is a VERY cheap option that might just end up extending the life of your injectors. For the $50 or less it takes to buy and install...I would strongly recommend this as a way to increase injector life.
Once I get my filters installed (installing a fresh OEM filter + prefilter at the same time) I'll keep everyone posted if I encounter injector issues.