I believe that it would be in the consumers best interest if Budweiser and Corona merged. Both companies are very well known for their product. If the companies merge we might see new innovation in either of the brands that was not possible before. Also, distribution costs may be reduced and those savings could be passed to the consumer.
If Corona and Budweiser merged their individual brand image would become blurred and non-defined creating a less desirable brand. Corona would no longer have the face of a fine Mexican brew. It would have no clear image. Would it be a Mexican-American beer? Would people begin to add rice to it instead of lime? It's really a fine, blurry line that should not be crossed.
Budweiser has no reason to merge with Corona. It is the strongest alcohol brand in the United States and is very popular. There is no reason to merge these two companies. Budweiser would not be gaining anything from it and Corona could die off and not many people would be upset.
Budweiser and Corona are to distinctly different brands. Merging the two would seem some how to affect the brand identity of the other. Kind of like if Pepsi and Coke merged. It just would not seem right. It would seem to dilute the brand quality of both products. Both Budweiser and Corona already have strong brand identities, merging the companies together would potentially affect them negatively.