Preview at WWDC likely in June, followed by September launch.
Apple Already Preparing Some Early iPad Mini Pre-Orders for Shipment
The first pre-orders of Wi-Fi models are scheduled for delivery on Friday, November 2, with Apple typically arranging with delivery companies to have shipments held until the launch date. It is not unusual, however, for a handful of orders to slip through early.
Apple sold out of its launch-day stocks of the white iPad mini models in the United States within minutes, and with the company still offering launch-day delivery on the black models it appears that supplies of the white models may be especially tight in the early going. Orders for Wi-Fi models in many other countries went to shipping estimates of two weeks essentially immediately upon opening, while cellular-capable models are projected for mid-to-late November availability.