This is to follow up the ticket 2784525: http://sourceforge.net/tracker/?func=detail&aid=2784525&group_id=182424&atid=901159. Sorry that some how I didn't get the request for responding, the email might went to spam. And I don't seem to be able to re-open it.
A list of unit test support features of the current extension for 1.2 is listed below and can be found in http://code.google.com/p/kennethxublogsource/wiki/CommonLoggingExtension for better readability.
* Each InMemoryLogger maintains its own sink, so you can write assertions easily.
* InMemoryLogger's log level is by default dynamically connected to the log level of the InMemoryLoggerFactoryAdapter. This let you change log level of ALL InMemoryLogger by just one call to the factory adapter. So that you can quickly write unit test case with parametrized test feature to ensure the code works with logging enabled and disabled.
* Level on each logger can be certainly overridden.
* The InMemoryLoggerFactoryAdapter provides method to obtain the InMemoryLogger instance by name or type. The return type is InMemoryLogger in nature so you don't have to cast it from ILog.
* The factory adapter has ClearAll method to clear all sinks maintained by the loggers.
* factory adapter has ResetAllLevel method to reset the level of all loggers to make them back in sync with factory log level.
IMHO, those features I found to be useful and convenient to use during unit testing. But I guess there is always a workaround for it.