To respond to some of your other questions - one thing that we've noticed isn't super clear is that Dream is not doing any form of desktop sharing. We integrated chromium at the native layer (by way of a forked version of CEF) and the content views are all web browsers. This allows for a level of integration with the rest of our stack in a way that is difficult or impossible to achieve if you're doing desktop sharing (we actually built desktop sharing, but disabled it in the build for now until we can solve some inherent usability problems).
We're big fans of Bigscreen, but I think they're heavily shifting their focus on entertainment and watching movies in VR together. Also, we were working on Dream for 1.5+ years when Dash was announced and were excited to see some similar ideas there! We're trying to find ways to make VR as a viable solution for remote working and collaboration, and this has led many hard decisions we've had to make - especially as we've decided to build the entire stack. This obviously meant it took us a lot longer to get something out there, but as a result Dream is a lot more intuitive and seamless than you might expect.
For example, our keyboard was heavily inspired by an early Google VR experiment we saw, but after building out a version of it we quickly understood why it wasn't getting people to a viable text-entry solution. We built our own collision system and "interaction "engine" to allow views and apps in Dream to respond at the event level of "touch start, touch end" similar to what you'd expect in building an iOS app - and underlying this the interaction engine would be updating the collision / position of everything in real time. As a result, we've seen people hit 30-40 WPM on our keyboard due to the tactile cues we've included (audio/haptics) as well as a kind of activation region, which allows you to really time and feel out the key press. Definitely hard to describe this or show this in videos since it's all happening at 90 FPS - but hey, it's a free download so give it a shot!
Dream never asks you to revert to your monitor or take off your headset, this was a strict rule. This means that everything from logging in, to inviting someone new to your team had to be possible in VR. To accomplish this, we create a kind of chromium integration with Dream so that we could run web views that manipulated our engine directly. To us, asking the end user to remove their HMD for any reason is equivalent to asking them to restart their computer - it's really not acceptable.
Our goal is to demonstrate how immersive technologies like virtual reality can enable remote collaboration and communication use cases. Especially in terms of how VR, by comparison to existing 2D formats of video/voice, provides an improved layer of presence through nonverbal communication cues.