Version 4.6 and associated Update XX was the last of the "it will release when it's ready" releases.
Starting in April of 2014 we have moved to a regular feature release cycle of April and October.
The first such release is numbered 14.04, the next release in October of 2014 will be 14.10. The subsequent release will be 15.04.
There may be bug fixes between feature releases and these will not be at planned intervals but instead as needed. The first bug fix release for 14.04 will be 14.04.1, the second 14.04.2, etc.
We start feature release planning before a current release is actually completed. Just because an issue is planned to be worked on in a particular version doesn't mean that it will be completed within that version. If the feature or issue is not completed or satisfactory by the time code complete arrives (approximately 2 months before release) that issue will (at the discretion of Product Management) slip to the next release.
The best way to watch the progress toward any given release is the sipXcom Project Roadmap page in the issue tracker. If you see lots of Unresolved issues, the release is probably not happening soon. If you don't see any Unresolved issues, it probably is soon (note however, that some problems known to QA and/or the developers may not have been filed yet, so the picture is not always perfect).
The issue tracker is how we track everything we're doing... to see the flow for how an issue is created and progresses, see How to Report a Problem or Request a Feature.
Two important things to note in an issue:
Plans sometimes change, but you can use the Priority to get some idea of this:
For getting a feature or issue into a given release, the process is as follows (features are broken down into one or more issues):
You should also understand Version Numbers.