I expect that players, managers and umpires will continue to adjust to the way the game is called and the casual baseball fan won't really notice much difference from last season. Some people might want to compare this rule change with the one in 1969 when the height of the mound was lowered because pitchers were starting to dominate. The strike zone is much more subjective. The biggest complaint I've heard from batters is the called strike just off the outside corner. I'm not sure the men in blue have stopped giving the pitchers that one.
Old habits are hard to break.
Even if umpires are able to stick with the new directive, the size of strike zone might not be the antidote to high scoring and long games. Maybe there just aren't that many quality pitchers out there. Pedro Martinez and Randy Johnson have shown they don't need any extra help from the umpires. Yet expansion has watered down the rosters, and young pitchers are being asked to learn on the job in the big leagues. Unless you're a power pitcher, you're not going to get away with throwing a high strike anyway because it's a lot easier for hitters to make adjustments.