So today's the day (perhaps not the Saturnian day, but close enough) that Saturn is at equinox. The gas giant's axis - and therefore also its ring plane - is neither tilted towards or away from the sun. With the sun's light striking them edge on, the Cassini imaging team's favourite frame of reference - the illuminated/unilluminated side of the rings - will be briefly meaningless, before turning on its head.
The Cassini homepage has a nice article on the event here, but as always, you're probably best off checking out Emily Lakdawalla's eloquent description at the Planetary Society blog here.
Disclaimer: the Hubble image above actually shows Saturn from 1996-2000, leaving an equinox and heading into the northern winter that would greet Cassini.