The constant struggle between pitcher and batter is one of the core elements of any baseball game, real or digital.
MLB 08 managed to nail this duel, leaving very little for
MLB 09: The Show to improve. For pitchers, the Pitch Command System allows them to look at an opposing batter and determine what pitches work best against them based on tendencies. As a counter-measure, Progressive Batter Performance allows them to use a pitcher's tendencies to determine where the ball will most likely go. Both are great systems, though it is apparent that the PS2's age may be starting to show when it comes to using each. While at bat, swings feel a little slower, so you need to add some delay in order to accurately hit the ball. Though not a major adjustment, it makes enough of an impact that it can throw off your game.
Fielding always seems to be an issue in baseball games, and receives the most attention in MLB 09. Between pitches, you can access a menu that allows you to quickly shuffle your fielders around or adjust their reactions to certain situations. This helps a lot and gives you the flexibility to react to just about any batter, pitch or game situation. Player stats also seem to play a greater role. Players with low-reaction times will bobble and even misread balls more often, which results in slightly more realistic fielding than the magnetized gloves and metal balls of years past. This also plays into their reaction time when balls come their way. The unfortunate downside to this is the increased number of errors, which is a bit troublesome. Even the better teams seem to create more errors than they logically should. Again, it doesn't kill the game, but it makes enough of an impact that it will throw your game off.
If you're still not able to upgrade to a PS3, but still want to go to "The Show," MLB 09: The Show offers a problematic, but enjoyable experience.