The answer is incorrect. AWE can be used in 64-bit and some people recommend that it should be set because it helps SQL Server manage memory by not allowing the working set to be trimmed. (Note: lock pages in memory must also be set.) This blog entry explains it pretty well.

http://blogs.msdn.com/psssql/archive/2007/10/18/do-i-have-to-assign-the-lock-privilege-for-local-system.aspx