As you may have seen on the WordPress.com news blog, we turned on slideshows today.
Here's a brief intro to how it works:
When editing a post or page, add images using the Media button as you normally would. When you're done uploading images, click over to the Gallery tab in the Media pop-up (you may have to press "Save Changes" at the bottom to get the tab to show up). At the bottom of that gallery screen, you'll see a button for inserting the slideshow. Click the button to insert the shortcode.
If you'd rather do it manually, then the shortcode:
will drop the slideshow into your post. It will automatically use all images that are attached to the post.
Go nuts! Use it to give your visitors a neat way to experience the photos you've added to your posts. If you have any suggestions for the feature, you can either leave them in this thread or send us a Support request. If you're experiencing trouble with the slideshow shortcode, we definitely want to know, so send us a Support request on that, too.