With the end of the PSM program ending, how does one Sony plan to support development of games in Unity for the Vita? Do I apply to the regular development program? Is it still as open/simple? Can I still use a retail Vita to test?
What do I do?
I am afraid you will not be able to use the regular retail kits even as test devices. There is a connection process between PSM developer key and your PS Vita which will no longer work after May 31st.
If at all possible you will want to get your hands on a development kit for PS3/PS3/PS Vita - this will allow you to use Unity on these platforms. Please note that Unity will require authorisation from Sony before releasing their plugin for Unity that allows you to target Sony platforms.