Important move by two mobile giants. Vodafone and Orange announced they will share their radio access networks (RANs) in the UK. Of course, such a move will not be completed short term, but will be gradually implemented over a number of years. Rationales behing the move are named better efficiencies, reduced capital, lower opex, and better coverage. So they are in a win-win agreement, but competition between them will be unchanged as they do not share their core networks.
It is likely such agreements would multiply over coming years.