I couldn't find anything about Ubuntu acting as a Miracast receiver or sender.
- Can it work at all?
- Are there hardware prerequisites?
- Is WiFi a requirement or can it work over LAN or another kind of network connection?
- WiFi direct seems to be a necessary requirement, is it a sufficient one? (i.e. if a system supports WiFi direct does that mean it supports Miracast?)
- Are there differences in support between receiving/sending?
- How is the latency? (compared to the competition, i.e. VNC, commercial Miracast devices, etc.)
- How do I actually use it, if it's difficult?
Specifically, I plan to use it together with an Android phone (4.x Jelly Bean).
OpenWFD is dead and now superceded by MiracleCast:
It's still early in its development cycle. Currently it seems like it can do the linking, but won't do the actual video streaming.
The OpenWFD demo at FOSDEM 2014 also did the streaming bit, but as I understand MiracleCast is a do it right project, whereas the code he showed at FOSDEM "will probably only work on this machine".