Description of problem: insert a short section after "3.4. Configuring yum" called "Enhancing yum" that details (at least) the improvements that Presto and Fastest Mirror provide. There is not a current consensus on whether Presto will be enabled by default on F12 (though signs point toward "no" due to lopsided speed differential re: older machines/slower drives). Suggested course: provide short section on ways to enhance yum.
In addition, new xz (was: lzma-utils) default payload compression for RPM should be mentioned. Appending this change to this bug.
Presto plugin documented: http://documentation-stage.bne.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html-single/Deployment_Guide/#sec-Plugin_Descriptions
Note: The RPM chapter contains the mention of XZ compression as a new feature. Also, XZ compression is mentioned in relation to createrepo. See:
Setting to ON_QA.