A very vague question, you have to tell us what do you exactly want to know of a life of a DSLR. Is it shutter life? Is it body life generally? etc. For shutter life, it depends on how you use your DSLR and whether the shutter is a defect. 90% of the time, your DSLR's lifespan mainly depends on how you use it.
Nikon's D3 shutter is rated at 300,000 cycles. Do your math. If on average you are going to take 200 shots per each week, which is equivalent to 6 rolls of film, shutter will last for about 60 years. How old are you, by the way?
it depends on so many factors, not just how often you bring it out for a walk
1) how much you shoot each session
2) how well you treat your camera, might play a part i suppose, if you drop your camera or bump it around a lot i guess it will not last as long?
3) how well the manufacturer had manufactured your shutter unit
so many factors, how to tell you
don't ask, just shoot
if you need it professionally then get more bodies as backup
if backup body also cui then suck thumb and give up, the powers that be don't want you to take photo, so be a good boy/girl
as mentioned already; most shutter units are rated for 100k shots for higher end models
i think lower end models ~50k depending on brand
but got people reflect 7k their shutter unit kena
some people beyond 100k already still snapping away happily
Aiya...can last a long time one lah. My point and shoot camera, lend to this friend, that friend, scratch here and there, still happily snapping away. It has been four yrs now.
It seems to me you are asking how long before the camera goes out of production and they don't make spare parts, lens, and such that you need to change camera if it spoils? Anyone has the answers? I dun
dude there is one reason your camera cant last you a life time...its called wear and tear. nothing is perfect in this world and something is bound to give way sooner or later (although most of us would prefer later)
a) you bought your camera at 80yeras old
b) you dont really use your camera very much and rather leave it sitting in ur dry caninet
The question is how much later. its a matter of when not if.