I always turned off Action Center in Windows 7 - is there anything new in Windows 8 worth keeping it around for?
Action center (in Windows 8) also now reports if applications are impacting startup time. That's a good enough reason for me to leave it enabled, but obviously your own situation may be different.
From Keep tabs on performance in Windows 8 with Action Center on TechRepublic:
Designed to provide protection against phishing Web sites and malicious downloads
Clicking the View activation details takes you to a Control Panel applet
In addition to the activation details, you can use the links to purchase additional copies of Windows 8 or learn more about the license terms
The Microsoft account feature links your Windows 8 user account with what is currently called Windows Live and is designed to seamlessly provide access to all sorts of features in the cloud, such as photos, documents, and other files from places like SkyDrive, Facebook, and Flickr. You can also share status and contact info with Hotmail, Facebook, Twitter, and LinkedIn. Of course, this is all optional and configurable
This feature that will automatically perform maintenance tasks such as software updates, security scans and system diagnostics. If you click Change Maintenance Settings, you can choose the time that you want the Automatic Maintenance
File History is a new feature in Windows 8 that works like a combination of Previous Versions and Windows Backup and Restore
It's up to you to decide if you keep it or not.