This month's release includes a change to the CKEditor configuration, aimed at improving the editing experience for users.
When you select "Filtered HTML" as the text format for the body of your content, you will only see buttons to format text as bold, italic, bulleted list, and ordered (numbered) list, as these are the only options supported by this format.
If you need to apply more extensive formatting and want a more complete WYSIWYG editing experience, choose "Full HTML" as the text format, and the editor will show you a wider range of buttons, allowing you to format text, add media such as images, and other HTML components.
Please note that if you switch a page from Full HTML to Filtered HTML or Plain Text, you will strip away any formatting you had added.
Pro tip 1: If you would like Full HTML to always show up as the first (default) option when you create new content, go to Configuration -> Content Authoring -> Text Formats, click and drag Full HTML to the top of the list, and click Save Changes.