Thumper,
1) Cant think of how you would connect up headphones, there are two outputs, one for normal speakers and another for line level out if you want to use it. I would imagine maybe one of those wireless headphones might be possible to hook up alright.
2) Each sonos box (on the zp100) has 4 lan ports, effectively giving you an extension of your broadband through these ports. I am using one of them to connect my xbox360 to my BB. Just plug it in and it works!!
You could connect up a laptop, as you say, but if I would rather use a laptop wirelessly with a wireless router to be honest.
3) The new features added last week were improvements to the overall music management on the controller, improvements in scrollwheel sensitivity, and best of all, alarm clock functionality. I now wake up in the morning to my sonos playing either a pre selected play list, or else streaming radio, which ever I want. I time my kitchen zone to com on about 5 mins after the bed zone as well (as long as its a weekday).They also added snooze functionality etc as well. One other thing they added was I think Rhapsody, whcih is a service which basically is an internet jukebox. It is a subscription service, but sounds pretty cool (not availalbe to subscribe to outside the US yet though).
My set up is 6 zones and 2 controllers. I have as I mentioned connected my xbox to my broadband via a sonos box in the living room. I also have a wireless router, whcih I use for the laptop, so my first sonos box is hooked up to this too. My music is all stored on a desktop pc, but I plan to move all this to a Networked hard drive eventually so I dont need the desktop anymore.
One otther hany feature, is that controller software can be installed on any pc/laptop on your network giving you full control from that pc also.
Hope this helps, do have a look at
www.sonos.com the forums are very very good too for info. Let me know if you need any more info.
Regards,
Eamon