As we’re seeing now with Apple’s current MacBook Pro line, delayed shipping dates and sell-outs are often good indicators of an imminent product refresh. Discounts are also a good sign that a popular product is nearing the end of its life. With that in mind, new reports of retailers and carriers showing dwindling iPad inventory or discounting Apple’s tablet could be indicative of an impending next-generation iPad announcement. 9 to 5 Mac reports that British retail giant Carphone Warehouse is sold out of the 64GB iPad Wi-Fi as well as each of the three iPad Wi-Fi + 3G models. Carriers Orange and T-Mobile have slashed prices on current iPad inventory in half, so customers can now get an iPad for as little as £99.99 on a two-year contract. Finally, European retailer Ingram Micro is sold out of three iPad models, and is showing low inventory on the other three versions of the iPad. Apple is expected to launch the iPad 2 in March, though the company has not made any official information available surrounding the device.