Only about 8% of retail purchases are made online but well over 50% are influenced by online research / information. Shopping has really already gone "web" and "web" local...
The transactional impact is already happening too. You've got Site to Store options where you can buy online, pick up in store. You've got Amazon prime at 2 days now and making a push for 1 day. And you've got a select number of online companies doing their own local delivery.
As shoppers we don't care about divisions, logistics or any other internal stuff. The mantra is we want it, get it to us but stores and web teams have struggled with this not because of technology but rather their own walls. Merchants have built out separate teams with no benefit to store sales, thus they live in isolation that way. Web teams are composed of people who buy a lot online, thus they're limited in seeing the value of the store. Local businesses who are most likely to see the return on being truly multi-channel just lack the resources, so they're limited too.
To your point there's a HUGE opportunity here and it's hardly being capitalized on but it has started. The way things are going now I suspect we'll see big returns from Amazon -- not because they're geniuses at this but because everyone else is sitting on the sidelines while they watch the world demand something and slowly build up to deliver it.