I think that an important thing to update in the actual FreePBX 2.4 version is the paging mode.
The paging mode is not as efficient as it could be because it is only a one way call to many phones. The called phones cannot reply.
Since version 2.4 it is possible to activate the paging duplex mode, but this gives 2 major drawbacks :
the background noise becomes higher as soon as the number of paged phones rise.
the communications can be heard by everyone in the company sitting near a paged phone. This is specially true with device and user mode, if the user has logged on more than one phone.
A good paging system need to be a simplex system during paging, and become a duplex intercom when a user press a digit on one of the paged phones, muting or cancelling all other phones.
This works like this on analog intercom / paging since decades.
Actually the system works more like a Public Adress (PA) system, not a true paging/intercom system.
Almost every well known phones today are supporting intercom mode.
When a group of phone is in one way paging mode, it should be only a feature on the asterisk side to switch a particular phone in duplex mode, and cancel all other calls in the group.
To trig the switch from one way paging mode to intercom duplex mode, a simple press of a digit on one of the paging group phone could advertise asterisk through an applicationmap ?
This interactive feature would transform the PA like FreeBPX paging to a true Paging / Intercom system.
To allow for a greater flexibility, i think that it is important to take into account user rights. We should be able to decide wich user or device can switch from simplex paging to duplex intercom. It can be desirable to forbid some phones or users to reply to a paging announce.