Corporate Sponsors on Uniforms at the World Baseball Classic

"Now batting, #7 sponsored by Best Buy, Ivan Rodriguez." It's not exactly how it went down during the opening day of the World Baseball Classic, but Best Buy patches were rather conspicuous on the uniforms sleeves of the Puerto Rican team in their game against Panama. While uniform sponsorship is prevalent during winter ball, one has not seen sponsors on uniforms during spring play. If this trend passes with little fanfare during this year's World Baseball Classic, how soon will we begin to see uniform sponsorship in Minor or Major League Baseball?
While the foreign countries may be used to having sponsors on their uniforms during league play, I am curious as to how the Americans will react to seeing their favorite players play under the logo of a major corporation. Is the Puerto Rican team ahead of the curve regarding opportunities to generate advertising revenue, or are they tainting the game by having sponsors on their uniforms?