Illuminated Cloud now displays the output of the Salesforce CLI's standard error in a toaster popup. This includes a clear notification when a new version of the CLI is available. IC will not automatically update the CLI because there have been occasional issues during CLI updates and I don't want to obscure those if/when they occur. I'll revisit that decision once I feel that there's no longer a risk when updating the CLI. Minimally, though, you'll know when a new version is available now via IC.