If you have a hosting provider that will work with you, MySQL has a bit of tuning that if done to tailor it to your installation and their system, can help a bit.
The Script: http://mysqltuner.pl/mysqltuner.pl
Brent Peterson works with some well loaded Magento sites, and so has some my.cnf recommendations here for a server running 32GB, a bit out of our league unless you scale some of the settings down:
Some recommendations for mysql parameter tuning using mysqlreport recommendations:
Anything that makes MySQL respond faster and clear out its requests faster helps, the caching mentioned in the previous post help Magento serve out more static type content which reduces the requests to MySQL in the first place. This is where LightSpeed page caching helps immensely. You serve cached pages to the search engines and guest customers which gets you down to 300-500ms html response and requires MySQL involvement only for dynamic content that you have allowed, all the rest emulated static content. Without it, Black Friday would have been Black along the line of lights out instead of more sales.
Another big help in taking the strain off the web server is to use Amazon CloudFront to serve out just the images (media), though this just frees up resources on the server for other activities, not necessarily directly involving db server performance.