The choice between diesel and hybrids is easy, says David Welch, an analysist with BusinessWeek - there really isn't one. Car companies need to be working on both to be competitive around the world, due to trends in different markets. The article claims that the average cost of a diesel engine is $1000-3000, but that upcoming emission requirements will add "several thousand" to that cost and bring them into parity with hybrids. There's also the driving styles that each technology is best suited towards, which of course then begs the question as to why the urban Europeans prefer diesel while the highway-cruising US market is leaning towards hybrid. If manufacturers can find ways to deal with the upcoming stricter emission requirements - and I'm confident that solutions can and will be found - then it will be interesting to see how the market shakes out.