This comes out of the LinkedIn module brainstorm issue, here:
http://drupal.org/node/740690
Basically, we got talking about how we are going to map data coming back from LinkedIn to specific CCK (Drupal 6-)/core (Drupal 7+) fields. I noted I was always wanting to do this, but never managed to tackle the problem properly. For example, the NITF Views module could do with some interface to allow you to map fields to specific elements of the NITF schema. My XML Parser module could do with some kind of field mapper UI too. So could LinkedIn. So could dozens of modules, I'm sure.
Feed Element Mapper used to do this:
http://drupal.org/project/feedapi_mapper
http://developmentseed.org/blog/2008/jan/24/build-your-own-mapper-feed-e...
But it's been rolled in to Feeds and is no longer a separate module.
So, should we start a project offering a generic mapping API for fields, like Feed Element Mapper, that any module can use when it needs to present a UI for mapping a set of "stuff" to individual fields? Or should we not allow Feed Element Mapper to die, maybe?
Thoughts?

Comments
I think this is a classic use
I think this is a classic use case for Feeds. Write a Feeds parser for the LinkedIn format (NITF?) and done.
http://www.twitter.com/lxbarth
Cool
LinkedIn is a web service, I'm not sure what flavour - I haven't done any dev work on it yet, personally.
But to give you a practical example I know I need:
NITF Views module is a feed output for the Views module in the NITF format. At the moment we make assumptions about which bits of a node map to which bits of the NITF XML schema and hardwire it. It would be great to be able to actually map CCK fields to NITF elements in an admin UI somewhere and for the Views style to just pick that up when it renders the output.
I can do this with Feeds?
Anyway, I probably don't fully understand how Feeds works - I'll read up! Thanks! =)
I'm confused as to whether
I'm confused as to whether you're looking to map incoming data to Drupal entities (the LinkedIn example?) or expose Drupal entities in a specific format (the NITF example?). Are you looking to do both in one mapper?
Either way, for outbound mapping I use a lot http://drupal.org/project/views_rss .
FYI - mfer and Crell are working on a larger solution to standardize the description of Drupal content (e. g. in Atom) in order to facilitate writing sources and consumers around such a standard.
http://www.twitter.com/lxbarth