I ordered DayZ to support them. If you order Alpha access, you get a discount on the final version coming out next year. The lead developer stepping down is not a bad thing. There are many more developers on the team. He just wanted to focus on survival more than the others, and he was probably outnumbered on how to proceed with development.
FYI: We shouldn't call it the "DayZ Standalone" because any game is technically a standalone. We don't say "Battlefield 3 Standalone" - it's just Battlefield 3.