No there isn't. Auto-advancing sliders can't be added to an existing WordPress.com theme that doesn't already include that feature, either through the Custom Design upgrade or in any other way.
These are themes that have featured posts image sliders http://theme.wordpress.com/themes/features/post-slider/ In most of the themes with featured post sliders, visitors have to click to advance the slider to the next featured post. Some themes have a featured post slider that automatically advances: Debut, Currents, Linen, On Demand, Modularity Lite. (the first 4 are premium themes) and the last one is a free theme. Sight is also a free theme with an auto-advancing post slider.