Hi Dave,
As promised, I popped into Vodafone Oxford Street this afternoon to take a look at their Serenata package. It is as you described it, a £50.00 a month contract with Vodafone, plus an extra £100.00 for the Serenata. However, the helpful afro-man assistant also mentioned to me that everyone who had bought the Serenata from them returned it almost immediately. 26 were returned during the month of February and swapped for another phone.
The Serenata will not be locked to Vodafone as they have all simply been bought straight from the B&O store on the Brompton Road, Knightsbridge where they are of course all unlocked to any network.
Initially this deal seemed quite good to me, but now less so if people really do not like the phone. You must also really want one in the first place to get one, yet they're still being returned. I am on a corporate contract, so the package will not interest me personally. For now I'm doing fine with my Serene and the BlackBerry Curve.