As Lar recently described in the topic A quick status update, the Xbox versions of DKS were submitted last friday and the PC versions should have been built over the weekend (so the final QA check is in progress). When that is done they can build the FoV versions (don't know if they are testing them at the same time, or are going to finish with DKS first), at which point it should be clearer whether and how they can provide a D2:ED+FoV to DKS conversion patch.
If so, hopefully they will have the time to include it on the FoV DVD (or at least the larger resources that will need to be replaced), assuming the publishers agree, and don't mind the increased production costs if it that would bump it to a dual layer DVD.

I can not see charging for such a patch, since the whole motivation for its proposed existence was people complaining about how the few details we have about the remastered aspects were so fantastic that there was no point in playing the patched original version (which, regardless of how may times it was played or hours enjoyed, would pale to rubbish in comparison), and yet the very idea of paying anything over and above the unknown cost of the add-on to get DKS was unthinkable.