Truly wireless - Battery Powered PLAY unit

You would have to consider Wi-Fi or Bluetooth... as portable may be out of range for your Sonos network, but not from your device (if it has some music library on it)... Then Bluetooth would work for headphones too, when back within network range... I experience this at a friend place, a wall was obstructing my iPhone, while his IPad was still in range... this was 7 ft just outside... This are issues I don't have with Jambox, thus the possibility to switch from Wi-Fi to Bluetooth when needed.

would love to rock a sonos at my husbands cyclocross races. And other tailgate situations.

I'd buy a couple!  Something like the Pioneer  A3 XW-SMA3-K but not as "muddy" sounding!

Add my voice to this request.  Most of the requests here are a little old (before there was a Play:1) and refer to the Play:3 and Play:5.  The killer version for me would be the Play:1 because of its small size and weight.  The battery should definitely be rechargeable (while still playing), but the battery time does not have to be terribly long - 3-4 hours would be plenty.

For comparison, you should look at the Tivoli Audio PAL radio.  It is a similar size and easy to carry around.  I have one and often carry it to a different room, or outside to do gardening or work on the car, or throw it in the laundry basket when going back and forth.  But, sadly, it is JUST A RADIO, not a SONOS!

I would definitely buy a Play:1 Portable if it were available.  Personally, I would probably not buy a Play:3 or Play:5 Portable, because I think they would be too large to carry around while I also have other things in my hands.

Ideally, incorporating lithium battery/recharger in the Play with Bluetooth! The charging unit should have the ability to work off the car plug or if available USB port.

I don't think that SONOS will do this. Unless they charge a huge amount for the rechargeable portable, they are asking people to opt out of a SONOS for every room and instead buy the one SONOS that they can easily move about. I think the cord annoyance is why I spent the money on one for every room when I would have opted out of the bathroom and garage if it were easy to grab one from the kitchen or something.

I don't think that SONOS will do this. Unless they charge a huge amount for the rechargeable portable, they are asking people to opt out of a SONOS for every room and instead buy the one SONOS that they can easily move about. I think the cord annoyance is why I spent the money on one for every room when I would have opted out of the bathroom and garage if it were easy to grab one from the kitchen or something.
I think you are missing the point.  The same music everywhere, including the garden, bathroom and outdoor rooms is the aim so I don't need to carry a speaker with me, otherwise it's just a radio or MP3 player you are describing.

Bose and Samsung have just announced a Sonos like system and they will have battery versions. If Sonos doesn't keep up, they may loose out.

I don't think that SONOS will do this. Unless they charge a huge amount for the rechargeable portable, they are asking people to opt out of a SONOS for every room and instead buy the one SONOS that they can easily move about. I think the cord annoyance is why I spent the money on one for every room when I would have opted out of the bathroom and garage if it were easy to grab one from the kitchen or something.
No, I'm not missing the point. I'm saying that after buying the basics...living room, den, kitchen/dining, bathroom, bedroom...I'd probably not continue and buy one for the guest room, garage/workshop, sewing room, etc because I could get just one extra "floater" to carry between those less often used places. I can think of 3 units at least that I could consolidate into a portable in my home right now. I'm not implying people would buy just one unit total, but instead they would buy considerably fewer than they are forced to now.

I don't think that SONOS will do this. Unless they charge a huge amount for the rechargeable portable, they are asking people to opt out of a SONOS for every room and instead buy the one SONOS that they can easily move about. I think the cord annoyance is why I spent the money on one for every room when I would have opted out of the bathroom and garage if it were easy to grab one from the kitchen or something.
OK, fair point.  I'd use a Play:1 as a "floater" as it's easy to unplug and plug back in.  It doesn't drop the connection if you do it within a short space of time which surprised me when I first moved my Play:1.

I'd probably buy 3 battery units, a bathroom unit and two "outdoor" ones to suit the way I want to use them. 

I don't think that SONOS will do this. Unless they charge a huge amount for the rechargeable portable, they are asking people to opt out of a SONOS for every room and instead buy the one SONOS that they can easily move about. I think the cord annoyance is why I spent the money on one for every room when I would have opted out of the bathroom and garage if it were easy to grab one from the kitchen or something.
I just checked out the Bose with its new SoundTouch Wi-Fi series of speakers and Samsung with the Shape M7; not impressed.  Especially since the rechargeable is plug in instead of wireless plate or dock.  I'd love a Play 1 rechargeable (though my recent bathroom remodel already included power/ethernet in the bookcase just for it).  My only beef right now is the roundabout way to get podcasts playing via the computer where I don't use iTunes...I'd love to be able to pipe my Droid to Sonos the way I can pipe it to my beats headphones.  The next gen should add a way to play such audio via bluetooth profile or whatever it takes.  This is off topic.  Please forgive.