I think the difference this time is that if Google controls the browser AND the biggest websites, then they'll be more confident introducing features that lock you into that browser (See the offline storage bit mentioned in the article). With those lockin features more common, people will be less willing to support other browsers in the future, because they wont be able to offer those exclusive features. With that large userbase that can use cool features like those, other large websites will take advantage of the proprietary API's (see, the issue with webkit css prefixes right now). Lack of possible support from users means most alternatives wouldn't be able to gain any traction, which is going to discourage any growth in that field.

A comparison I think is valid is if an