As it stands, most PaaS providers are largely targeted at custom code rather than packages like WordPress. But that doesn’t mean you can’t get WordPress up and running, as Amit Shah demonstrated by moving his WordPress blog to OpenShift.
Actually, he was moving from Blogger to WordPress, which makes it even more interesting. Shah gives a detailed explanation of how he moved his blog to OpenShift, including the commands to grab PHP, MySQL, add domains and set up the directory for WordPress.
Why would you want to do this? Scalability is one thing. I’m running a WordPress instance on Linode right now, and I can add resources if I want but it requires manual intervention and stopping/restarting the VPS to make changes. Hosting on a PaaS should mean you can scale up/down dynamically with no downtime.
It also means that the PaaS provider will take care of all the security updates. That’s true, or should be, if you’re using shared hosting or WordPress.com. However, the trade-off for shared hosting means that you’re on a server with who knows how many other users. It also offers much less flexibility. WordPress.com offers plenty of scalability, but again has much less flexibility in terms of what you can do (like install custom plugins, etc.).
One of the trends I’m hoping to see in 2012 is for projects like WordPress to be easily deployed on PaaS services.