One of the open requests we've discussed before is the idea of making it so users in VR can participate in some ways in text chat. Although this doesn't bring the VR experience to parity with the desktop experience, here is a proposal for something helpful:
In this scenario, the popup menu we currently have (mute, exit VR mode, etc.) would have a new button with maybe a mail icon to show/hide this piece of UI overlay. The "Chat" and "IM" buttons would show a number indicating active chat or private IM conversations that have seen updates since the user last was in Desktop mode. Teasers from recent messages would scroll as text overlays and fade away after a few seconds. This whole UI would be hidden by default; the user would have to activate it.
I realize this can take away some of the clean view, but this should be easy enough to add to the UI in a way that does not require storage of a preference or dealing yet with user interactions with HUD-type interfaces. Stuff just displays passively and it's up to the user to decide to switch out to Desktop mode to act on it.