UPDATE: The WSJ says the formal launch will be at Paris and Boeing will announce launch customers from the US (United, Air Lease Corp), Europe (British Airways), and Asia (Singapore Airlines). No word on numbers or if these will be firm orders.
I only have a 140 character tweet from Jon but he's reporting that Boeing is formally launching the 787-10 with orders from Singapore, United, IAG, and Air Lease being seen as possible launch customers. If true, this news comes 4 days before the start of the Paris Air Show and a day before the first flight of the A350-900 which the 787-10 will compete directly against. Obviously Boeing is trying to steal some of Airbus' thunder with tomorrow's first flight.