Well I can tell you that a lot of bulbs have not lasted 12,000 or even 8,000 hours. The real kick in the pants is that these bulbs can't be purchased at your local Home Depot as now your best bet is through the manufacturer or online store. Even if you can find the bulb you need, your likely going to pay a minimum of $100 (including shipping) just to get the bulb and then you have to hope your technical enough to replace it yourself (or have the added cost of paying someone to do it for you). I'd be interested to know if the manufacturers of these bulbs knew that the lifespans where not as advertised.
So you were just watching your trusty 6 year old DLP TV when all of the sudden you heard a "poof" sound and your screen went black. You can still hear your show and there is even a little red light blinking above the "blub" logo. The TV's instruction manual says that your bulb is fried and you need to call the manufacturer to order a new one. They tell you the bulb will run you $150 plus S&H. Do you get the bulb to rekindle the love of your 6 year marriage, or do you ditch the bitch and spend big dollars to get yourself a new slimmer, brighter, clearer mate? You really need to ask yourself the big question, do you NEED a new TV? Do you crave a better quality picture or a TV that you can hang on the wall? Can you afford a new TV? Do you have any high definition sources to even take advantage of the expensive beauty? These are all very important questions to answer before you take the plunge.
Some key factors also need to be considered before making your final decision. You could get your new bulb and then the ballast (internal power converter/supply) could blow and then you have to make another purchase. What was the lifespan of your initial bulb and are you OK with your second bulb not lasting as long (as replacement bulbs can be inferior in quality to the originals). New LCD, LED and Plasma TV's are rated at a minimum of 60,000 hours, that is nearly 10 times the realistic lifespan of a DLP bulb.