We just informed you that Lumia 620 will be coming to all major networks and operators in UK, Feb 2013 onwards. Now, Carphone Warehouse has put the pre-register page up for Lumia 620. They mention expected date as Feb 2013. So, in case the cheapest Lumia has caught your imagination, you can go ahead and register your interest on the page.
Lumia 620 pre-register page up at Carphone Warehouse, UK.