WordPress has some pretty great plugins for integrating your website with Amazon AWS.
One of the key features which can be extremely important to your website is the speed and delivery of any uploaded media. This could range from images, to videos, to podcasts. Amazon S3 and CloudFront allow you to use their Content Delivery Network to offer media in a low latency fashion. You can read more about Amazons CloudFront service at http://aws.amazon.com/cloudfront/ in order to make Amazon CloudFront easier to use (almost automagic) you can use theAmazon S3 for WordPress Plugin. This plugin allows you to upload all of your media to an S3 Bucket for use with Amazon CloudFront.
Along with the Amazon S3 for WordPress Plugin a nice plugin is the Amazon S3 URL Generator, this plugin allows for dynamic generation of expiring URLs to your media stored in S3. This protects your media from being hotlinked against.
Another important plugin for WordPress websites is the ability to maintain regular backups. I useWP S3 Backups plugin. This plugin allows you to define an S3 bucket to backup all important parts of your WordPress site, including your themes, database, plugins, settings, and media.
For all of our sites we use Amazon EC2 along with Amazon Elastic Load Balancing in order to provide highly available auto-scaling load balanced servers. This makes our websites highly available, and prepared to handle any traffic load thrown at it. Only the static WordPress files are maintained on these servers.
One final important peice of the puzzle is your database. As I stated before, our servers are only serving up the WordPress files. Our database is hosted in Amazon Relational Database Service (Amazon RDS). This allows us to maintain our database in a highly available, low latency environment that can be dynamically served from multiple datacenters based on geographical location.
Using these services can help make your website fast, highly available, and completely redundant and backed up.