Following the news that Orange and T-Mobile will be looking to merge is the news that O2 has lost the exclusivity deal to supply the iPhone 3GS to the UK market. In a deal that has been rumored about for the last few months Orange will be offering the iPhone to UK customer 'before the end of the year'.
The possible advantages to having more than one service provider is that the tariff costs should start to come down! No idea yet as to what packages Orange will offer but I think it's a given that they'll match and probably beat the O2 offerings from the start.
They're currently asking for people to 'register their interest' so if you fancy a shiny Apple iPhone 3GS with an Orange sheen, head over to their site: Orange Mobile
UPDATE: Hot on the tail of the Orange announcement is the news that Vodafone will also be offering the iPhone 3GS, visit the store to register your interest!