I talked earlier about Cloud Services, and many vendors like Amazon, RackSpace, etc. are used more for consumer services and enterprises are generally weary of clouds – part of it being paranoia and might be baseless (because of coming up with a process of doing things differently) and a valid reason being security (authenticating with Active Directory) and not wanting to part with services that are not totally in a business’s control, because this could be a business’s core or its IP.
But, the result is that there big  savings, so it is worth looking into.
So, understand and address all the inhibitions to move to a cloud.

Now, the solutions for these are quite vendor-specific (Azure might have them, while Amazon may not), so I’ll mainly talk about Azure.
I mainly see 2 hurdles in using Azure viz.
1. Authentication
2. Proprietary (in-house) Services

In the case of authentication, IT cannot really move the entire Active Directory to the Cloud (and should not), which means that we need a third-party authentication with Azure (that’s what its called, because Azure does not authenticate you then) and our company.
That is, a user uses Azure, but has to authenticate first and this is done externally on- premises of the company (known as on-prem).
This is known as an on-prem/ off-prem solution in industry parlance.

For this, we can use WCF with the Azure Service Bus.
From the Azure website:

Think of the Service Bus as a way to communicate with Azure, and the communication happens between Azure and your company.
So, via this mechanism, Azure can callback into your company, which addresses both authentication and the services issue.

This also means that you need modular services that can be called by someone, which is anyway a good goal to have.

To inform your IT, Azure also provides the following features:

Virtual Machines— Allows you to move your virtual hard disks (VHDs) back and forth between on-premises and the cloud.
Existing workloads such as Microsoft SQL Server or Microsoft SharePoint can be migrated to the Cloud.
Use your own customized Windows Server or Linux images, or select from a gallery.

Windows Azure Virtual Network— Lets you provision and manage virtual private networks (VPNs) in Windows Azure, as well as securely extend on-premises networks into the cloud.
It provides control over network topology, including configuration of IP addresses, routing tables and security policies and uses the industry-standard IPSEC protocol to provide a secure connection between your corporate VPN gateway and Windows Azure.

Availability in New Countries— As of now (May 2013), availability is expanded to 48 new countries, including Russia, South Korea, Taiwan, Turkey, Egypt, South Africa, and Ukraine, making Windows Azure one of the most widely available cloud platforms in the industry with offerings in 89 countries and in 19 local currencies.

Here are details, and an example for you as a developer – http://www.windowsazure.com/en-us/develop/net/tutorials/hybrid-solution/

So, the Cloud is not only for consumer services, and with a little planning, Enterprises can use it as well.