I think we certainly still need finding aids - the biggest worry I have in the LD world is that we lose the essence of archival theory, which is collections (and items) in context. One thing we need to preserve is not just the ability to be able to find items, but also to view the relationship between the items and their creator. Linked data shouldn't take this away, but instead enable tons of additional relational data (to other collections, creators, and concepts). I think the place of the finding aid in the future should be as one access point, instead of as the only access point.
I think the issue is not whether we can transform, because obviously we have been transforming EAD to MARC for a long time, but I think we'd all agree that MARC is not really an ideal way to look at an archival collection. The hope is that we can be part of BIBFRAME to break down the wall between "traditional" library resource description and archival description. Is it possible to have a data structure that works for both? I think so.