Dreamhost had recently launched the DreamHost PS premium shared hosting service (invite-only), available only as an add-on to a current DreamHost hosting plans. Now they have launched a DreamHost PS MySQL (a service completely separate from DreamHost PS), that gives you the same sort of memory and CPU isolation to push your databases to the limit.
Introducing DreamHost PS MySQL, they say that all MySQL databased on your account can be moved to your very own MySQL instance inside a Linux-VServer virtual private server on dedicated database hardware (means local, raided, high-performance SAS disks, used for shared DB servers). Now you can pay to upgrade your site to private server services and test new traffic bursts with exceptional performance uptime and avoid server crashes.
The pricing is $1/month per 10MB of RAM. If you buy both DreamHost PS and DreamHost PS MySQL, you get 20% off your monthly fee for both services! Dreamhost already has my vote for service performance.