I certainly wouldn't argue with the suggestion that DLP is worth a serious look, though I don't exactly know what you mean by "color sharpness." Depth, accuracy? LCD is, to some extent, more color-challenged than other microdisplays, in that it produces color by a subtractive process from white light. Plasma, for instance, has the three basic colors available from the outset, making for better chromaticity. LCDs tend toward oversaturation. Many people find it striking, regardless of the inaccuracy, because of the sheer glory of all that coloful resolution; others find the overdone greens and reds distracting. The drawbacks of the DLP color wheel are well documented enough in this thread, as well as in general, not to stand repeating now.

The shelf life argument has some validity, though maybe not so much as thought. Flat-panel LCDs might get the 55,000-80,000 hours of life that mfgrs. claim for them, under extraordinary circumstances, and even healthy plasmas may not be able to keep up. But in real life, the discrepancy might not be so large. Plasmas may burn unevenly, but not like they once did. The components that guard against such wear on the better plasmas actually work. But LCDs also have to be wary of contrast set too high, since the flourescent lights behind the screen will dim in time. These lamps also fail, and so far as I know, only Sharp LCDs allow for replacement. In most cases, as the lamps go, so go the LCDs. The bulbs on RP LCDs are much more user-friendly than those on flat panels. Maybe they're the ones you mean.

All of these technologies have their tradeoffs. But I would venture the guess that an informed consumer who is interested in a plasma for what it does well will not be easily swayed toward LCD for reasons of longevity and that someone inclined toward an LCD flat panel for its relative advantages might not find DLP a good substitute, despite its upside.