Work on the next release of Asterisk, version 1.4.20, continues apace: The Asterisk development team has released Asterisk version 1.4.20-rc2.

From the Asterisk web site:

This release is a release candidate for the upcoming official release of 1.4.20. It includes a fix for a SIP channel driver regression introduced in 1.4.20-rc1, among a number of other changes.

The release candidate is available on the download site.