Hello Jon, and others
B2 definitely does work with DLNA on a B&O wifi enabled speaker, as Paul and others have indicated here. As we know, recent updates have added a better interface for the very popular Sonos system, the consequence of which is that the B2 has to be set to operate with either Sonos or DLNA. So you have to go into the settings and make sure that DLNA is turned on, and I guess that NAS is also turned on, as that's what the B2 will be doing, ie acting as a server.
I don't know about any of the other enabled B&O units, but the sound from the Beosound 2 is very impressive, as is the look of the speaker - my wife also fell in love with that! The Beosound 1 has the advantage of being battery powered, so is completely portable, but loses some of the punch of the 2. In both instances, as Paul and others here note, the B&O will 'pull' music from the B2 rather than the B2 streaming music to it, but it has to be said that the B&O app that controls this is not a patch on the Brennan one. There's no album artwork, no intuitive searching, no easy interface. What you get is really just a representation of the file structure as you would see looking at the B2 using it as a NAS to your computer. You do however get random playing of all tracks, which in the garden is how we use it.
We have also found the connection of the B&O to be occasionally flakey, and it's not our router or signal strength, as we have loads of BT's disc extenders all over the house and outside, so never have drop-outs on other gear. I don't think we have the 5GHz/2.4GHz issue either, as the B2 does not lose its app control when playing to the optically connected system indoors. When the B&O drops out, it seems to revert to some playlist that I have never made, and I cannot see the other 9000 or so tracks any more. This is usually resolved by deleting the B&O app and re-installing - the equivalent of 'turn it off, wait, then switch back on' I guess. The app will then offer the choice of Bluetooth, DLNA or other connection, and find the B2 when DLNA is chosen.
In summary, the B&O wifi speakers work with B2, have a great sound for casual use, but I just wish they would come up with a better interface app.
rgds
David w