In a comment to this post, Robert J writes:

I don't have it in front of me, but my local paper mentioned that there were 39 blown saves in the first 99 games this year. Is this the beginning of a cycle of fewer dominant closers? Have hitters caught up to them?

If you look at games through yesterday (the 2nd Tuesday after the first Sunday night game) there were 58 saves in 94 opportunities in 2004, 43 saves in 87 opportunities in 2005. That's a save percentage of 61.7% in 2004, 49.4% in 2005. So this has been a bad year for blowing saves, although a 61.7% conversion rate isn't stellar.

Unfortunately I no longer have the data, but I believe league save rates have been in decline for some time. I remember doing studies when I was at STATS showing that the decline was coming entirely from middle relievers; that actual closers were pretty steady over time. This comes from managers not using their best pitchers in game situations, but saving them to start the ninth with a lead.

There's another trend that may have something to do with it; strikeouts are down slightly, 6.3 per 9 in 2005 vs. 6.4 during the same period in 2004. Are more batters trying to put the ball in play? Or is it that we haven't had much cold weather at the ball parks? Offense goes up with temperature, so an early advantage for pitchers may be negated by the weather.

Still, it's just 87 save opportunities. Just as anything can happen in 100 AB, this is probably just bad luck. It's a trend worth watching, however.