Here's a good article that summarizes the Imprelis situation well:
Some worthwhile information for homeowners provided in the article:
"DuPont has promised to settle with homeowners and others who have dead and damaged trees from use of Imprelis, but some trees are very old, and will probably be replaced with younger trees, changing the look of the landscape. It is also important that the trees be replaced correctly, to avoid contaminating the new trees." - this is something each homeowner must evaluate to see if the possibly permanent change to their landscape is valued correctly by Dupont. Also, will Dupont compensate for not just a tree/shrub of equal height to what was damaged or will they compensate for the height that damaged tree/shrub would have been at the time of replacement which could be 1' to 3' higher by the time the settlement is reached with the homeowner? For some with symetrical landscape, such as trees/shrubs lining each side of a drive, if one side was affected then the other side continued to grow past the heights of the damaged side. Therefore, a reasonable adjustment by Dupont to compensate for the height of tree/shrub it would have been could be demanded by homeowners.
Article above in link also provides more insight into possible lasting dangers:
"Because Imprelis doesnít break down, itís effects are also being seen at compost sites. Imprelis does not bind to the soil, and could conceivably seep into the groundwater as well. Composters are urged to take care with grass clippings. Clippings that come from Imprelis treated lawns, and wood trimmed from Imprelis damaged trees cannot be used as mulch, as it would infect the plants mulched with the product."
Source: Herbicide kills trees, recalled (02/08/2012)
By Frances Edstrom