Exchange Service Pack 2 was just made public and includes the Hybrid Configuration Wizard, which the team built to make it easier for customer to configure hybrid deployments. By "hybrid" deployment we typically mean a case where a portion of your organization's mailboxes are hosted with Office 365, and a portion are hosted by your on-premises Exchange server.

Ben Appleby has a nice blog post, Introducing the Hybrid Configuration Wizard, on the Exchange Team blog that explains what the HCW does. Here is a snippet of Ben's description, in his own words:

The Hybrid Configuration Wizard consists of:
 1. A new Exchange Management Console (EMC) wizard that guides you through the end-to-end process for configuring a hybrid deployment.
 2. A set of Exchange Management Shell (EMS) cmdlets that orchestrate the configuration process (as always, the EMC executes these Shell cmdlets).
 3. Improvements to the manageability of some of the underlying hybrid features (no more exchangedelegation.contoso.com or service.contoso.com domains – Yay!)
 

What does it do?
 
The hybrid configuration cmdlets take inputs from the wizard, analyze the state of your existing on-premises and cloud organizations, and calculate the required steps to correctly configure both organizations correctly. You can learn more about this process here [Understanding the Hybrid Configuration Wizard].

The last link is a good place to start for getting familiar with the wizard. More links to updated documentation will be coming soon...

Tony