Amazon kicking WikiLeaks from its Amazon Web Services does not mean in any way, shape or form that you and your company can't trust cloud services. Extreme examples like WikiLeaks are rarely applicable to the rest of the world and only show that extreme cases lead to extreme reactions. What WikiLeaks may show, by way of extreme example, is that end user license agreements (EULAs) and terms of service (ToS) need to be carefully reviewed prior to signing on the dotted line. Organizations can, and do, use cloud services and don't run the risk of being arbitrarily cut off. The slippery-slope argument that Amazon kicked WikiLeaks and they will kick you too is FUD. Don't let extreme corner cases drive your cloud strategy.
Let's break down a cloud service to what it really is. Regardless of type, a cloud service is no different from any other outsourced service you may use, including co-location, hosting, virtual private hosting, SaaS or any other information processing for which you contract. Cloud providers offer a set of services, and you shop for the ones that best fit your needs. You have to agree to the ToS and EULA as part of the purchase process, and you should read and understand them before proceeding. If you think your company will run afoul of the terms--perhaps by hosting adult content, running a gambling site or publishing hate speech, all of which are common unacceptable uses called out in a ToS--then you need to ask about those activities before you commit.
Getting that clarification ahead of time is no different with any service provider. What did the WikiLeaks organization expect Amazon to do? Defend WikiLeaks' right to post the cables that clearly weren't theirs to post? We can argue what Amazon would of/could of/should of done with WikiLeaks till the cows come home, but that doesn't mean Amazon wasn't abiding by its ToS. We also don't know how cloud providers such as GoGrid, Rackspace, Microsoft Azure or Google, nor any other cloud providers, would have reacted.
The WikiLeaks situation is an extreme example of a single company, Amazon, refusing to do business with a customer and using its ToS as a shield. But WikiLeaks is just one customer out of how many that Amazon has? More to the point, how many customers are supported by all the cloud providers in the world? The Amazon/WikiLeaks case is isolated, and there is no indication that this is the top of a slippery slope where cloud providers refuse service or disrupt service because they "don't like" the content of their customers.
You should always be concerned about service availability and the ToS when dealing with a outsourced service, but there is no need to panic and no need to discount all cloud services as untrustworthy, or make specious claims of First Amendment rights violations. If you are going to host and make public (I think that is the critical part here) material that could violate a provider's terms of service, then you need to have that talk with the service provider before you sign up. For the rest of the organizations that aren't dancing anywhere near that line, do what you normally do to build trust in an outsourcer. If a cloud provider fits your needs, then forge ahead.