yeah but even if people sell their trucks, they will go to secondary markets, where they are seen as 'good deals' and so people will look at the 'savings' and use it as a reason to expend large amounts of $ on fuel.
Cant escape choices that were made previously... at least until the current set of cars go to the junkyards.
In reality, much wont change until clean diesels come out in large quantities, and maybe (though battery processing is polluting) hybrids get more popular in high-traffic areas, allowing drivrs to get 25+ MPG instead of the usual 8-10 for a normal car in daily traffic jams.
And at that point, it may be too late anyway. Cant change the choices made by consumers, and its bearing upon everyone. And that true whether were talking about vehicles, wal-mart goods, or whatever else.
JMH