I imagine there's something on the DPS forum somewhere already but figured I'd put this up over here too since Surecast is essentially a healer's Tempered Will.
With the 4.0 launch Surecast now provides the ability to nullify knock back and draw-in effects while the buff is active. This includes but not necessarily limited to Titan's Landslide and Aerial Blast and Tidal Wave inside The Royal Menagerie. I imagine anything GLD/PLD can and cannot mitigate with Tempered Will, healer's can and cannot with Surecast as they have very similar text.
As long as the buff is up, you retain this knock back immunity. The Surecast buff is consumed either when the timer expires or when you cast a spell that has a cast time associated with it. This also means if you make a spell instant cast with Swiftcast, the Surecast buff will still be retained.
Just some knowledge I wanted to pass on to other healers to think about when selecting their cross roles as Surecast definitely has some applications now depending on the fights.