I've owned a number of diesel vehicles - boats, trucks, cars, tractors. Currently own Ford, Kubota and MBZ diesels.
Historically, diesels have been desirable because of great low end torque, economy and durability (re-buildability). Hard haulin' trucks and high mileage travelling salesmen have been the primary benefactors of diesel advantages.
Modern gas engines and lubricants are improved to the point that the economy and durability difference is not that significant.
At the price differential of gasoline/diesel (diesel .20/30 cents gal more around here) and the initial cost premium of the diesel engine, the catch up may be several hundred thousand miles. A well manintained modern gas engine can be expected to perform well for 200k miles or more.
Most diesel engines require oil changes at less miles and use (usually a lot) more oil per change.
The torque differential remains, but do you really need 400 ftlbs to go to the grocery store. If you regularly tow a 6 horse trailer, then sure. The larger gas engines give up very little, if anything, in the performance department.
Diesels are relatively noisy (older ones are really noisy!) and smelly. Fuel is not at every station and costs more. You will get fuel on your hands (and feet where the fuel has been spilled) - it has an unplesant smell and does not just wipe off. If you've not had the diesel experience, it would be nice to rent or borrow one for a couple of days before purchasing.
Many, if not most, current diesel buyers would be better off, practically speaking, with gas engines.
The biodiesel, etc, "advantage" may or may not be real and lasting. I don't consider it. Whenever possible, I will never use anything but the best and freshest fuel I can find in my diesels. And I can't imagine putting any thing other than good, clean fuel in a new small, high performance diesel.
I'm certainly not anti diesel, just putting out a couple of real world things to think about. Were I buying a new vehicle, even a work or camper truck, I would probably buy gas.
I believe, and have posted several times, that there will be a real fuel crisis. Gas at and maybe exceeding $5 gal and sometimes not available. I think it's probable that diesel fuel will be more readily available than gas then (if it's not rationed to "critical" users - i.e. government, over the road truck, construction, etc.)
BTW - diesel fuel does not store well. Not good to lay in a long term supply.