For a long time motif has been the de-facto standard widgetset in the professional world. This had one major issue, and that being that the source of motif was not free by Debian standards. The Hungry programmers implemented a replacement called lesstif under a free license to provide a way to use free programs written for the motif widgetset. In 2012, the motif source has been relicensed, making the lesstif source redundant and obsolete, as its goal has been achieved, a free motif.
In Debian, we have had the lesstif2 package for a long time, but now we want to replace it with motif, which lived until now in non-free under the name of openmotif. It is our intend to remove lesstif2 from Debian before the release of jessie.
Updating packages that build against lesstif2-dev should be rather painless as you can just replace it with libmotif-dev. Some packages need to include explicitly some additional build dependencies that were pulled in by lesstif2-dev. We already filed bugs for those packages.
The progress of this transition can be followed in the bts by using the lesstif2motif usertag.
Debian Release Management motif transition tracker.
The request for removal bug 731678 was filed on 8 December 2013, which was closed on 11 December. The package finally was removed from testing on 25 December 2013, as documented in transition bug 708462.