So far, Asterisk-Java seems to work fine with the new release.
…and they followed up with 1.6.0-beta2.
For the 1.4 series they start providing release candidates, an idea that was discussed on the -dev list before and aims at providing better qualitiy for the final production releases:
The release candidate for 1.4.18 is only available via svn. It is available for anyone that would like to help test 1.4.18 over the next couple of days before it gets officially released.
Grab it from http://svn.digium.com/svn/asterisk/tags/1.4.18.