UPDATE, 8:32pm PST This looks kind of important: A's sign 17-year old catcher from Korea...
Instead of just walking everyone, like he did last time, Joey Devine mixed it up a bit, walking two and hitting a batter in a 7th inning in which the tying run scored without the benefit of a base hit. That left the A's, who scored 4 times in the 1st inning thanks in part to a Kurt Suzuki two-run HR, owners of a 4-4 tie.
Andy LaRoche remained red-hot, going 2 for 2 to jump his Cactus League average to a clean .409. Get it? Now jump to see how important I think relievers are...
...I get that relievers are often overrated, certainly overpaid considering how inconsistent -- and as a result, somewhat fungible -- they tend to be. You should not be throwing Jeremy Affeldt or Fernando Rodney money at guys like, well, Jeremy Affeldt and Fernando Rodney.
It's also true that while Andrew Bailey is a very good closer, he falls in the "most closers" category of being neither as "automatic" as Mariano Rivera nor as "gascanny" as Arthur Rhodes. You do need a good closer, but most teams have exactly that: A good one.
Here's where I do believe a bullpen can be a significant strength: Depth. While most teams have at least one excellent reliever, usually anointed to be the closer, and generally have another very good one, often appointed to set-up duty, what few teams have is enough really good relievers to shorten games by making 6th and 7th inning leads mostly insurmountable.
This is where I think you separate the decent bullpens from the ones that are actually special, and I am still optimistic that the A's will boast one of the league's most special bullpens. The core group of Bailey, Balfour, Wuertz, Ziegler, Breslow, and Fuentes will offer Bob Geren the chance to put a fresh reliever, well suited to high-leverage work, in as early as the 6th or 7th when needed, and it's unlikely that any of those guys will have to be used so repeatedly that their performance or health will suffer significantly. (And one hopes that by the time injuries or fatigue take their toll, perhaps Rich Harden or Joey Devine will look like a good replacement option, though admittedly they don't right now.)
It's counter-intuitive to think that your "4th or 5th best reliever" should be focused on as much or more than your "best reliever," but consider this: Many teams can match your best reliever or your second best reliever. What many teams may not be able to match is how deep you can go without experiencing a drop-off. This bullpen is one of the reasons I could see the A's surprising people in the AL West in 2011.