Well, no, sadly.
Consider this thought: if everyone in your city drove twice as fast, all the extra efficiency would make the local economy grow more rapidly. Right?
But wait - driving twice as fast only really works to save time and improve efficiency under some circumstances. What about residential areas and curvy roads? Can these cars even drive twice as fast all the time without falling apart and causing all sorts of other problems? Doesn't fast driving cause more noise and wear on the roads? Does it cost more to drive fast than the time saved adds to your income? Plus which there are always going to be people for whom driving fast is never going to translate into efficiency: they'll be at the beach or in the bar. I'm pretty sure that a large chunk of the economy has no relationship to how fast people are driving, in any case.
Your body is a complex system, and as such its properties - such as health and life span - are not necessarily directly related to the properties of its individual components. Like a city or an economy, your body is a process in motion, with more hidden depths than the mere sum of its parts might suggest. In many cases, tissue and organs have evolved to operate most effectively with a high turnover rate of individual cells, for example. Changing that is somewhat like trying to downgrade a precision engine. Damaged cells need to be removed from the system, and cancer is the ultimate expression of cellular longevity.
There are no doubt subsystems within your body that would benefit greatly from extended cellular longevity; specific tissues in which longer cell life spans would in some way put off the local advance of age-related degeneration. A number of groups are aiming at just this sort of goal in telomere research, attempting to produce therapies for specific, localized age-related conditions. For the most part, however, "extended cellular longevity" seems to mean "lots and lots of cancer." From the standpoint of the present scientific consensus, would take a challenging array of supporting biotechnologies to change this situation.
So, no, a focus on cellular longevity is not the way to be looking at present day research with an eye to applications in healthy life extension. Instead look at cellular damage and its repair: some classes of damage do indeed shorten the life span of individual cells, but that is not the reason why treating this damage is important. After all, some forms of age-related damage lead to cells lingering for too long, cluttering up the joint, or actively proliferating longer than is safe and damaging the body. Rather, we would benefit from medical technologies capable of repairing this damage because it has been demonstrated to contribute to the degeneration of biological systems within the body.
This is the way to go: identify the components, identify the damage, prevent or repair the damage. Whether it involves cellular life span along the way is somewhat irrelevant - we care about our healthy life spans.