Here is the T3010-1 Registered Charity Information Return which replaces the T3010B for charities with fiscal year ends on or after December 1, 2010. [ed. CRA has subsequently said the T3010-1 can be used for fiscal year ends after March 4, 2010]

Here is a link on the CRA website: http://www.cra-arc.gc.ca/E/pbg/tf/t3010-1/README.html

The new guide should be available in January 2011.