The AWS-3 auction may be over, and the bickering over the 600MHz incentive auction just starting, but there are still plenty of mysteries about how those expensively purchased airwaves may be used by one of the big winners, Dish. The satellite TV company and its chairman Charlie Ergen (now also taking the CEO role) have tantalized the US markets for several years now with hints of possible strategies – mobile, quad play, rural, wholesale. Dish has conducted trials of rural satellite-backhauled services and this week announced that Artemis would be using its spectrum to run a trial network, based on the start-up’s radical pCell technology, in California. A quick source of fees revenue, or a sign that Dish is interested…