The source archive apache-log4j-2.0-beta8-src.zip contains at the top-level:
This is unnecessary and confusing.
The two LICENSE files are similar, except that the Appendix in LICENSE.txt has been amended from
Copyright [yyyy] [name of copyright owner]
Copyright 1999-2005 The Apache Software Foundation
That section of the license file should not be updated; it is a template for 3rd parties to use (and could probably be dropped as it is not part of the AL 2.0).
The two NOTICE files are very different; NOTICE starts "Log4j Distribution"; this is wrong, it should be "Apache Log4j" and the leading blank line should be dropped.
NOTICE.txt starts OK, and has two attributions.
Are these both required?
Are you sure both notifications are required?
Given the discrepancy with the other NOTICE file is very unclear what has happened here and what is correct.
Also, I cannot find any reference to Dumpster in the source archive; only included bits must be referenced in N&L files. [Later] I see the source was copied to a new package
It's not obvious in the binary archive either, but I suppose it could be hidden in one of the jars.
The LICENSE.txt file in the binary archive has been modified same as in the source archive. Looks like an attempt to automate changing the NOTICE dates has failed and managed to mangle the LICENSE as well.
It's vital that NOTICE files are as short as possible.