1) What's wrong with the 787 Dreamliner? No one knows for sure, now that the simplest and most easily correctable problem -- some production defect in the specific batch of batteries involved in two recent incidents -- appears to have been ruled out.
2) Which means that the problems are by definition worse than they originally appeared. Not necessarily worse in a fundamental-safety or design-defect sense, but worse for Boeing and the airlines in commercial and reputational terms, because it will take longer to be sure what exactly has gone wrong and what it will take to correct the problem.
2A) It is still likely that this will ultimately prove to be one more "glitch" in the roll-out of the 787, rather than a "threat" to its commercial and technological viability. Most new airliners have early problems as they go into service. But no one can be sure that this is in "glitch" category until the problem is fully understood.
2B) This is "one more" glitch for the Dreamliner because of the multi-year delays that arose from Boeing's unusually aggressive outsourcing of the plane's design, as I discussed in China Airborne and as the LA Times exhaustively examined two years ago.
3) Today's most trenchant data point comes from Elon Musk (above), one of the Atlantic's "Brave Thinkers" from two years ago, whom I interviewed at our 'Atlantic Meets Pacific' conference late in 2011. In an email exchange with Zach Rosenberg of Flight Global, Musk says that the lithium-ion batteries in the Dreamliner are "inherently unsafe" in the configuration Boeing has chosen for the plane.