I'm sure many people were waiting for this feature for long and it is now finally here
http://en.support.wordpress.com/slideshows/
I would just like to submit one thing: I think the slideshow shouldn't be turned on by default, instead it should let the audience touch the button to play. Hoping the shortcode would provide the key to turn the auto-start off.
The blog I need help with is webwanderings.wordpress.com.