Currently the node configuration information specified in cassandra.yaml can only be viewed via JMX or by looking at the file on individual machines.
As an administrator, it would be extremely useful to be able to execute queries like the following example;
select concurrent_reads from system.node_config;
which will list all the concurrent_reads value from all of the nodes in a cluster.
This will require a new table in the system keyspace and the data to be loaded (if required) during the bootstrap, and updated when MBeans attribute value updates are performed. The data from other nodes in the cluster is also required in the table.