Following my previous thread, Amazon is listing both machines at 5pm EST on Wednesday for lightning deals. Let's hope they can beat the $4200 plus tax for the X-Men deal on Tuesday.
EDIT - The Avengers Pro has disappeared from my deals list and just the Metallica is now listed for 8/6/14. Perhaps they are doing one per day and moved the Avengers to Thursday. I'll update if I see a change.
EDIT 2 - The Avengers Pro is up for 8/7/14 at 5pm EST.