I love (note the sarcasm) to hear people who are lucky enough to get a truck with no problems bash owners who do, just because they have a misplaced sense of defensiveness thinking their truck's good name is being tarnished. I hate to tell you, but I exclusively use ULSD from reputable, high turnover retailers. My truck already qualifies for the lemon law here in AZ. I have had both a turbo and a particulate filter replaced. These problems are real, and people are not complaining just because they are malcontents. My truck has also asked for new oil every 2500 miles so far (of course it only has 6000 miles on it since it has been sick a good portion of it's life).
There is good news, however. When looking at these problems, you have to consider numbers - and while there is a significant number of trucks with problems, there seems to be many more without problems right now. There has also been some encouraging results from the dealer recently. The latest flash is encouraging. The replacement particulate filters are encouraging. Right now I am still having a problem with mileage (13 city and highway unloaded), but the performance is impressive, even compared to my 05.
Personally, I figure that compared with the risk of modding with a programmer while still under warranty, the risk involved with buying a 6. 7 is far less. Dodge does seem to be supporting us with these problems so far (it is a little disturbing when they start blaming owners for idling too long), and the performance of my '07 is decidedly improved over my '05 in all areas (save mileage, of course . . . ). I love this truck when it is running. I even like the front end now, and the taillights are growing on me . . .