www.pepsi does look broken, but http://pepsi/ is fine. We just need browsers to stop ignoring bare TLDs, like they do now if you don't put the http:// before.
For example how would the Google Chrome browser work (and search to a degree), does a user who types "pepsi" into their omnibar want to go to http://pepsi/ or search for pepsi?
It also adds confusion for webmasters trying to parses URLs on their website. When a user types pepsi.com/coke into their blog for example that link can be made clickable to http://pepsi.com/coke/ where it can't for pepsi/coke