Yes, the Oracle Fusion Applications Help (or "Help Portal" to us insiders) is now available. Click the link fusionhelp.oracle.com and check it out!
Oracle Fusion Applications Help user interface
If you're developing your own help for Fusion Apps, then you can use the newly published Oracle Fusion Help User Interface Guidelines to understand the best usage. These guidelines are also a handy way to get to the embedded help design patterns for Oracle Fusion Applications, now also available.
To customize and extend the help content itself no longer requires the engagement of your IT Department or expensive project work. Customers can now use the Manage Custom Help capability to edit or add whatever content they need, make it secure and searchable, and develop a community around it too. You can see more of that capability in this slideshare.net presentation from UKOUG Ireland 2012 about the Oracle Fusion Applications User Assistance and Support Ecosystem by Ultan O'Broin and Richard Bingham.
Manage Custom Help capability
To understand the science and craft that went into the creation and delivery of the "Help Portal" (cardiac arrests all round in Legal and Marketing Depts), then check out this great white paper by Ultan O'Broin and Laurie Pattison: Putting the User into Oracle Fusion Applications User Assistance.
So, what's with this "Help Portal" name? Well, that's an internal (that is, internal to Oracle) name only and we should all really call it by the correct product listing name: Oracle Fusion Applications Help. To be honest, I don't care what you call it as long as it is useful. However, these internal names can be problematic when talking with support or the licensing people. For years, we referred casually to the Oracle Applications Help or Oracle Applications Help System that ships with the Oracle E-Business Suite products as "iHelp". Then, somebody went and bought Siebel.
Game over.