I was looking for an answer to just this question, so thanks for doing the research. I'm leaving the country in early October and if there"s a new mini with enough improvements over the mini 3 I would buy one to take along. A 9/19 availability would give me enough time to test it before my trip.
My sort-of-dil has my ipad 2 and my son has my ipad 3, so I would give him my ipad air and dil would get the ipad 3. We'd all be happy with that turn of events, as the ipad 2 is beginning to falter.