Well maybe the new Spriest "nuke" could be a final timer value for MF so that when it finishes casting your MB does more damage...
Wait sorry I confused Spriest with mage my bad...
Ummm a free automatic 4th tick of MF if you channel the whole spell and don't clip the last tick? (Still only 3 ticks in the channel just a 4th "magical" tick gets tacked on like a SW)
On that note a full channel of MF could remove the backfire on SW to make it less risky that you'll end up blowing yourself up (13 stacks of instability and I wasn't paying attention leave me alone >.<)
Mind Flay could also have a chance (Maybe glyphed or talented) too refresh the cooldown on Mind Blast.
And yes it's all about the mind flay but it's the iconic shadow priest spell so why not ^_^.