With most of the effort going to Jitsi Meet, and Jitsi Java client being a lot of work to maintain, I guess the natural evolution is a web-based HTML5/JS/WebRTC client application (although some argue privacy issues with browser-based webrtc - http://www.linphone.org/technical-corner/linphone-web/overview).
What's the current status for this project proposal?
Maybe Jitsi-Meet could be used as a simple "web phone" even if a "jigasi-like" module would be necessary to support SIP.
I haven't had time yet to fully test jitsi-meet & jigasi but: would a LAN client connecting to Jitsi Meet (I suppose via xmpp authentication) be able to dial a SIP/IAX2/DAHDI extension on an Asterisk server via jigasi sip gateway?
However, Jitsi-Meet is probably only designed for conferencing and features such as call transfers, etc. won't be supported.