Cloud vs SOA
What is Cloud Computing?
Customers to Vendors: You integrate Your products and give me a bundle to create a service.
What is SOA?
Vendors to Customers: Here is all my point products exposed as services(API) and You integrate my products to create Your service.
It's the question of who is doing integration! The basis for web-services technologies are all about integration and is the reason it exists in both buzzword.
Any one wants to disagree?