SQL Server 2008 R2 Standard Edition not using more than 32GB for BufferPool
In case someone reads this article in the future, SQL Server 2008 R2 on Windows Server 2008 R2 Enterprise (upgraded in-place) can and does use 64 GB RAM. Windows was patched last week and rebooted. 

After reboot:

select counter_name, cntr_value&lt;br&gt;
from master..sysperfinfo&lt;br&gt;
where [object_name]='SQLServer:Buffer Manager'&lt;br&gt;
and counter_name in ('Total pages','Target pages')


Result:

counter_name      cntr_value&lt;br&gt;
Total pages          7077888    &lt;--54 GB
Target pages         7077888    &lt;--54 GB