The LHC is reasonably multipurpose but since it's just a very high energy particle accelerator, coupled with a bunch of detectors, it's main areas of usefulness are within particle physics. It's unlikely that experiments conducted via the LHC will provide any immediate benefit towards the development of new technologies (although it probably will do for particle accelerators and detectors!). However, one shouldn't view such comments as being dismissive as to what other benefits the work will produce: the so-called Standard Model of matter has many implications and associations with dozens of other fields within physics, and so far the model has stood up very well to the huge amount of experimental testing it has received. Results from LHC tests will either help to reinforce the model, as well as offer new extensions to it or even, perhaps, show that certain aspects of the model are fundamentally wrong - all useful knowledge to have, I guess. As for the LHC's longevity, well the LEP (which the LHC replaced) ran for 11 years - I should imagine that the new accelerator will probably run for longer than that, because the cost to upgrade/build an even higher energy level one would require decades to plan, design and fund before any kind of construction can take place (the go ahead for the LHC was back in 1995). However, although it'll be sometime before the main ring is replaced again, the LHC's capabilities will be upgraded sooner than that, by virtue of the fact that the injector systems will be overhauled and have their energy values increased.