I am currently serving as the IAB-appointed liaison to the Open Mobile Alliance (OMA). My counterpoint on the OMA side is Ileana Leuca, who is copied on this report.
The relationship between IETF and OMA is defined in an approved draft that is currently in the RFCED queue. The text is available at:http://www.ietf.org/internet-drafts/draft-iab-oma-liaison-00.txt
Ileana has been instrumental in establishing a publicly-viewable collaboration-tracking page on the OMA web site at:http://www.openmobilealliance.org/collaborating/ietf.html
This page currently contains a first-pass at dependencies, although I expect many more to be reported as the relationship and process gets socialized through the OMA community. There is already a strong social network in-place linking IETF-aware or participating OMA delegates with< the various IETF working groups working on related topics, and as a result I expect the overall relationship to continue to function smoothly for the forseeable future.