In real time I liked Bud Black's decision. Let us take a deeper look.
To reset the situation: top of the seventh inning of a scoreless game. Jon Garland had retired the first two hitters, and was ahead of Blake DeWitt 0-2. DeWitt singled softly to right. Garrett Anderson, on the next pitch, singled through the hole between first and second, DeWitt to third. Russell Martin is the next hitter, and pitcher Chad Billingsley is on deck. Joe Thatcher is warm in the bullpen. Garland had thrown 97 pitches.
What should Black do? Martin is 4-11 (including a 1-2 in this game) with a walk and hit batsman against Garland career, and 1-4 with a hit batsman against Thatcher. But looming on deck is Billingsley, who has retired 9 of the last 10 Padres he's faced, the lone exception being Yorvit Torrealba who he hit in the ribs with a fastball.
Black decides to walk Martin intentionally to force Torre's hand. Torre says "OK", and sends Andre Ethier up to pinch hit. Now Black could bring Thatcher in, but he decides to stay with Garland. Just for argument's sake:
Ethier vs Garland: 3-8, 1 double, 1 walk.
Ethier vs Thatcher: 2-8, both doubles.
Of course, if Garland retires Ethier, this blog post isn't written and the game might have been different. Actually they might still be playing. But instead, Ethier takes a 1-1 pitch and hits a ground ball just out of Everth Cabrera's reach, driving in 2 runs and as it turns out winning the game.
There are many, many folks who despise the intentional walk in any situation. I think there are times when the intentional walk is appropriate, and should be used. To get past a hot hitter or a good hitter, for instance. Martin isn't hitting any better since the All-Star break than he did the first part of the season (.245/.346/.332 before, .269/.345/.346 since), so I definitely would not classify him as hot and, based on how he's hit since the end of the 2008 season, not a good hitter either. There's a reason he's hitting eighth.
In hindsight, I don't like Bud Black's decision. I think I pitch to Russell Martin. I recognize that statement doesn't carry much weight since we know what the result of not pitching to him was.