The short answer is no. Zack Grienke--unless he completely and utterly implodes--is getting it. He all but wrapped it up with his amazing 15-strikeout performance.
That said, why isn't Rivera in the conversation?
I know, I know. He pitches one inning per game. Blah, blah blah. And yes, that thought does trickle through to those who vote for the Cy Young. But it's not unheard of; Eric Gagne won it in '03, Dennis Eckersly won it in 1992, Mark Davis won it in 1989, and Steve Bedrosian won it in 1987; Mike Marshall in '66[I may be wrong on that year] (all of them with stats not as good as Rivera has right now).
(Not that this should matter in this year's voting, but)Mariano Rivera got totally hosed in 2005. Bartolo Colon won the award over him, yes he had a good season, but let's look at the numbers: Colon had a respectable 3.48 ERA and 122 ERA+ (neither of them his best numbers in those categories for his career). Rivera, on the other hand, had a 1.38 ERA and a preposterous 307 ERA+. Batters had a .177 BA on Rivera that season (compared to .254 for Colon.) Rivera didn't give up a run May 6th to July 8th - a span of 23 games. To me, Bartolo did not dominate. That's what I look at when I think Cy Young...did they dominate? Mariano may do it for roughly 1 inning a game, but he dominates.
It's scary to think this year Mariano has probably been more dominating. Since June 16th, Rivera, in 29 innings, has given up 13 hits, 1 run and has 29 Ks. Opponents have hit in the neighborhood of .130 BA off him in that span and have batted .199 over the season. That number (BAA) drops to .167 with 2 outs and RISP. His WHIP is a ridiculous .898 (which, incidentally is not even the lowest of his career; both 2008 and 2005 are lower--of course he didn't win the Cy Young either of those seasons). I haven't even mentioned his inability to walk a batter. He has a miniscule 9 BBs allowed this season. Wow.
Not that it matters this season, but his career WHIP of 1.0136 is the third lowest of all-time, and the two pitchers ahead of him last pitched when World War 1 was making headlines. Oh, and his lifetime adjusted ERA+ of 201 is the best....of all time. By 47 points.
These are just his career regular season numbers mentioned. I haven't even touched on the fact that Mariano owns the post-season(except when Luis Gonzalez is batting.....). In 117.1 innings pitched in the postseason, Rivera has given up 72 hits to the tune of a 0.77 ERA. His WHIP is .750. His K/BB is an insane 6.00. His lifetime K/BB of 3.93 is 4th all-time.
Of course though, neither of his career numbers or post season numbers should be taken into consideration for this year's Cy Young. But, I thought they were worth a mention in this.
Mariano has probably been the 3rd most dominating pitcher in his ERA(Pedro Martinez and Greg Maddux - both of whom have won Cy Youngs. But, I know they are starters and Mo's a closer).
All of this is not to say that Grienke doesn't deserve the award--he is a viable candidate. But as you can see, for as good as he has pitched, it really hasn't helped his team all that much(how's last place KC?). Rivera, on the other hand, comes into a game in perilous situations, where his team hands him a game they can win--but need him to close for them. The pressure he pitches in makes 1 inning seems like 9.
Tom Kelly once said of Rivera: "He needs to pitch in a higher league."; Dennis Eckersley said Rivera is "The best ever, no doubt."; Alex Rodriguez once said, "If my daughter's life depended on it, I'd want Mariano Rivera closing." What else is there to say?
Just my .02