As part of a larger look at the sin of lust, Beliefnet is rerunning a 2002 piece by Rabbi Shmuley Boteach (whom I disagreed with last week). The upshot is that lust is OK if it's directed towards your wife.
But there is no reason people should feel guilty if they focus their lust in the right direction. By restoring lust to the marriage bed, we can avoid adultery and broken marriages.
Now, if the rabbi is using "lust" merely as a synonym for "desire," then there's no problem with these words. Indeed, dictionary.com defines it as simply "Intense or unrestrained sexual craving." (Although even here we see a difference between "intense" and "unrestrained.")
However, we think of lust with a fairly negative connotation for reasons that are not puritanical. For although desire is perfectly normal and even necessary for a healthy marriage, it can be corrupted by selfishness to the point where a man no longer desires his wife as a person, but as an object.
Boteach's point is that the kind of desire that is sinful when directed outside the marriage isn't necessarily sinful if it's directed towards the spouse. That's all fine and good, but the seven deadly sins are not just external expressions, they are also internal dispositions, meaning they can corrupt the heart, even if not acted out. This is why the Rabbi Boteach's contrarian position does more harm than good.
Men should desire their wives, and surely many marriages flounder due to a loss of such desire. But in an age where utilitarian sex is the norm, we should be wary of giving the green light to all of man's sexual impulses.
There is much else that is wrong, or at the very least weird with Boteach's article, but alas, work calls.

However, we think of lust with a fairly negative connotation for reasons that are not puritanical.
You almost anticipated my reaction, Chris.
I would state it somewhat differently: the fact that "lust" and "desire" are synonomous is a result of America's theological history. (Didn't Cardinal George say that in America, everyone's a Calvinist, even the Catholics?) We as a society cannot seem to grasp the idea that sexual desire has both rightly and wrongly ordered manifestations; for us, it has to be universally one or the other. If sex is always wrongly-ordered to begin with, then all desire must be lust, and thus, I think, is born the confusion of terms.
I think the following paragraph is particularly illuminating:
The idea that lust can and should be indulged, even in the proper context, may sound contradictory. Religious people in particular have been conditioned to believe that in order for sex to be sanctified, it must take place only with the intention of procreation--otherwise, the logic goes, engaging in sex is sinful. That view, unfortunately, snuffs the passion not only for casual sex, but for married sex as well.
He sounds to me like he's trying to articulate what a Catholic would call the dual purpose of married sexuality, but he can't (or doesn't) see that the language he uses is presuming no distinction between desire and lust.
The piece as written gives me the pip, too.