Two leaks for ICS for the Droid 4 have been found...one a few weeks ago (.200) and one early this week (.206). Users are reporting that it is extremely stable and very complete (the .206 being more so than the .200).
However, there is no way back to stock and .200 can't be upgrade to .206 so neither may be able to upgrade to the official ICS.
With that said.....I would expect the official release in late June or early July. The absolute latest....August.