What does this mean for domain names?

Sam Grobart, New York Times Bts Blog, A Is for Amazon, B Is for Best Buy: “On the Web, there’s another way a single letter can enhance a company’s prestige. Go to Google’s home page or browser toolbar and type a single letter into the search box. The search engine will then drop down a list of suggestions, based on overall search activity (you have to have “show suggestions” checked for this to happen in your toolbar). There are 26 sites that have the distinction of being the first suggestion for each letter of the alphabet.”
Interestingly, except for d for dictionary (where dictionary.com is the first result), all of these searches are for specific brands, rather than generic keywords.