Regardless of the ins and outs of the law in this case (use vs republishing rights for the data file, for instance), I don't see that there's any upside for OpenDDR continuing down the path of using WURFL fields.
A Device Database must be kept up to date, or it's going to do more harm than good. I think it's underestimated how bad at detection a device database can get after a few months of not being updated, given the number of devices being released.
Many of the fields in WURFL are specific to WURFL: i.e. the data in the field has no equivalent anywhere else on the Internet. So, given that OpenDDR claims it's working off a very old data file, how exactly are those fields going to be populated for new devices?
It seems to me that there's no practical, economic or sustainable way to keep OpenDDR up-to-date on these "extended" fields other than its users populating it independently with data derived from a licenced version of WURFL: which of course would not be allowed. I simply can't see a sustainable way forward for OpenDDR in its current form that doesn't involve repeated infringement of WURFL licenced data over time.