Velocity 2X preorders are open on Best Buy:
https://www.bestbuy.com/site/velocity-2x-critical-mass-edition-ps-vita/6008901.p?skuId=6008901&ref=199&loc=FKSJxY2VJAk&acampID=1&siteID=FKSJxY2VJAk-1Xt3MP8yORka_a.mWx08AQ
For those who haven't picked it up yet, Steins:Gate 0 is $25 on Amazon:
https://www.amazon.com/Steins-Gate-0-PlayStation-Vita/dp/B01JHQUTF8/ref=cm_cr_arp_d_product_top?ie=UTF8
Aqua blue PS Vita is down to $169.99 at Gamestop again...tempting
http://www.gamestop.com/ps-vita/consoles/playstation-vita-system-aqua-blue-gamestop-exclusive/125335
No they won't automatically, sadly. You can contact them to refund you the difference but you don't want to overdo that as they keep tallies on that so you'll have to decide if the difference is worth it. The best thing to do would be to cancel and reorder (if it is still cancelable).
Ah man, maybe we should all plan to buy at the same time to throw off Amazon's algorithms. We'll call it the Value Interruption Targeting Amazon, aka VITA.
Corpse Party Everafter Edition is currently $39.45 on Amazon:
http://www.amazon.com/Corpse-Party-Blood-Everafter-Edition-PlayStation/dp/B00YMIQTII/ref=cm_cr_pr_product_top?ie=UTF8
Maybe its just bad luck on my part but every time I did a store pickup for anything that wasn't available the same day, items (amiibo, dvds, tools) always came damaged as they were delivered in bubble mailers to the store. Hopefully they have refined their delivery system.