Four modern checks have been added to Trusted Advisor to supply recommendations related to Amazon S3,Amazon Redshift, Amazon EC2 Reserved Instances, or security. Additionally,the service limits check now includes IAM. These checks provide further guidance to help provision your resources based on AWS best practices.
Amazon S3 Bucket Versioning (modern): Checks for Amazon Simple Storage Service buckets that attain not have versioning enabled, or have versioning suspended. Underutilized Amazon Redshift Clusters (modern): Checks your Amazon Redshift configuration for clusters that appear to be underutilized. Exposed Access Keys (modern): Checks for access keys that have been exposed to the public and for Amazon Elastic Compute Cloud (Amazon EC2) usage that could be the result of a compromised access key. EC2 Reserved Instance Lease Expiration (modern): Checks for Amazon EC2 Reserved Instances that are scheduled to expire within the next 30 days or have expired in the preceding 30 days. Service Limits (Updated): Added Identity and Access Management (IAM) limits to the service limits check, or to include items such as number of instance profiles,roles, server certificates, and groups,or users in an AWS account.
Source: amazon.com