I assume its for this reason (and others) that even Amazon.com still uses Akamai. Stuff like product images/banners still get served from domains like g-ecx.images-amazon.com (which resolve to Akamai)

CloudFlare seems to be rapidly expanding both datacenters and peering partnerships. Isnt the effective capability the same between both companies?

Is there something that Akamai can do that CloudFlare cant?

There is something which Akamai does and CloudFlare doesn't want to (at the moment): pay big sums to those big ISPs which refuse to peer and want to sell very expensive direct connections.

What does this mean for the company/application using CloudFlare or Akamai?

Both services seem to be highly available and very fast from around the world. What does Akamai do here that's better?

Akamai has direct connections to those "difficult" ISPs, CloudFlare uses transit to reach them.

To provide an example: transit to DTAG via GTT (CloudFlare) is always saturated at peak hours. So Akamai has a big advantage (direct connection) if you want to reach Deutsche Telekom customers.