One of the hallmarks of Microsoft is that we dream big - Steve 'Understatement' Ballmer
The member's list is intriguing, including as it does BT, Brazil Telecom, Cegetel, Eurotel, Korea Telecom, NTT DoCoMo, Rogers Cantel, Swisscom, and Telestra. So it's not just a knee-jerk reaction from fixed line operators (BT) reacting to the threat from mobile operators (DoCoMo).
It's strange that certain players - like O2's parent, MMO2, aren't included as O2 already offers such a service in Germany. Also - as BT has linked to Vodafone to offer such a facility, it is puzzling that Vodafone has reportedly declined to join.
The stated aim is to speed up the time-to-market for converged products. For example, BT has been promising the Bluephone (which utilises Bluetooth to provide the link to fixed lines) for some time but its existence is questionable.
It also seems to be a response to Wi-Fi, rather than an attempt by operators to negotiate price discounts for suppliers - which has been the motivation behind recent mobile network operator alliances. ยต