Primarily I am waiting for Wily Werewolf (*buntu 15.10) to go End Of Life in 19 days: http://fridge.ubuntu.com/2016/07/07/ubuntu-15-10-wily-werewolf-reaches-end-of-life-on-july-28-2016/

Once that happens I only need to test against Trusty Tahr (14.04) and Xenial Xerus (16.04) for backports as they'll be the only things supported at the moment. I wouldn't need VMs in that situation even. There's a machine in the house running Lubuntu 14.04 and I am running Xubuntu 16.04.

If you haven't upgraded off Wily...this is your casual reminder to do so promptly.