I can't edit and expand my original comment, so there's also this:
The DFRPG and some sort of other treatment (OSE and Shadowdark being two prime candidates) are each their separate efforts, as the rules and tone of each game are different, and the fanbase of each deserves a game properly adapted.
Additionally, I have to look at some of the IP issues - while Prootwaddles (for example) do not appear in this adventure, there may well be some TFT-specific monsters that would benefit from stand-ins or new critter creation.
So I do them one at a time, and never mix systems within a project.
I can't edit and expand my original comment, so there's also this: The DFRPG and some sort of other treatment (OSE and Shadowdark being two prime candidates) are each their separate efforts, as the rules and tone of each game are different, and the fanbase of each deserves a game properly adapted. Additionally, I have to look at some of the IP issues - while Prootwaddles (for example) do not appear in this adventure, there may well be some TFT-specific monsters that would benefit from stand-ins or new critter creation. So I do them one at a time, and never mix systems within a project.