I messed up. My son wanted Borderlands 2 for his XBox so I ordered it from Amazon, but its taking 8 days to arrive. That's a long time for a kid. I'm saving him $15 by using the Free Super Saving Shipping, but he really wants it now. (I've since discovered that Amazon Prime can be shared with family members, so my brother added me to his account and now I get free 2-day shipping!) I think he's typical of many shoppers, which is why there's renewed focus on next day shipping.
I'm trying ShopRunner, which is a club that offers free 2-day shipping for several retailers, including one of my favorites, Newegg. It's well integrated with the Newegg site so its very easy to use. Of course its 2-day shipping from when the order is picked, so it can end up being 3 days. Several retailers have created their own free-shipping clubs because free shipping is very important to web shoppers, and fast shipping delights. In fact, shipping charges and shipping time account for 76% of cart abandonment.
Now that Amazon has agreed to charge sales tax in Texas (where I live), they are opening three new fulfillment centers in Texas. This should make it more cost effective to offer cheaper, faster shipping. With enough scattered fulfillment centers, they could conceivably offer next day shipping to most major population centers.
Not to be outdone, eBay is testing same-day delivery in limited markets via its eBay Now product. Basically it tracks inventory at nearby stores, sends a courier to buy the item, then delivers it to your door for a fee. There are several similar services being tested in limited markets.
This is an area where brick-and-mortar stores might just have an advantage over online, especially if the Marketplace Fairness Act goes through and levels the tax playing field. Being able to ship items from a local store can be cheaper and faster than fulfilling from some warehouse on the opposite coast. Retailers that have already mastered "buy online, pickup in the store" need only change the pickup to delivery. Grocery seems to be focused on this, with Fresh Direct leading the way in New York and AmazonFresh in Seattle, not to mention the many successful offerings in the UK which are projected to double in five years.
I think the lesson here is that fast delivery is becoming a differentiator in some markets, so retailers would be wise to make sure the basics are ready. Make sure perpetual inventory is accurate and visible, labor scheduling is efficient, and shipping/delivery partners in place.