Let's all understand some things. JVC does not make the lamp...nor do Sony, Epson, etc... The manufacturers spec a lamp and have companies such as Philips, Osram, etc...make them. In the case of the RS40/50/60 and consumer equivalent (they are the same lamp and model...you don't see the talks about the consumer issues as they sell way less here where these are discussed) the lamp filament was inadequate to begin with. That is why there were so many premature failures. The newest version has fixed the issue and the RSx5 series have those. Part of the reason you still see RS40 people having issues is use. Some people can take 2 years to put 300 hours on a unit, so they may just be getting to an issue.
That being said, JVC and your dealer should be able to work out a fix should you have an issue with the lamp. Do note that ALL lamps will dim so it is only the cases of "out-of-the-norm" that are of concern.
It does stink, but things like this can happen in electronics as we all know.