Thankfully, you just got answers to a few of those questions through a Microsoft evangelist's presentation at an Israeli event. To start, he notes that any Bluetooth- or WiFi-based device can talk to it, and it'll run any universal Windows 10 app. And yes, you can link multiple headsets for a shared experience, even over the internet.
Battery life can vary wildly depending on how you're using the device, and it won't necessarily be good for everyone. At most, you can expect about 5.5 hours; push the HoloLens hard enough and you can bring that down to 2.5 hours. You won't be wearing this during a full work day, in other words... not that you'd likely want to wear it for that long as it is. Also, battery and cost will limit the field of view in the initial model to the equivalent of a 15-inch screen about two feet away. That view could get wider over time, Microsoft says, so don't give up hope for a completely immersive screen.
Given that the HoloLens doesn't even ship to developers until sometime early this year, it'll be a little while before you can understand every last nuance of how the device works. And the odds are that the eventual home version will have significant changes. Think of this as setting baseline expectations, then -- hopefully, it only gets better from here.
