I'm sorry to take issue, but I think you can read his words in another way:
We can also accept payment in a growing number of ways. In addition to single-payment packaged software, there are also schemes like monthly fees or per-item charges. I think this variety of payment methods will bring about a diverse range of playing methods, too.
Monthly fees could be TITLE SPECIFIC, i.e. MMO style. Note that the statement seems to be targeted at the software, title-oriented, not the network. There's nothing in those statements that seem to indicate the WHOLE PSN will come under a fee, or even tier itself like XBL.
Also, per-item charges ALREADY EXIST, on both networks. Did you download a Pirates of the Caribbean Sackboy costume for $1.99 or order the film editing pack for Skate2? Yeah, that's the same thing and in no way construable as a "monthly fee for PSN". As such, it indicates nothing about any future need to purchase PSN time.
There's also an excluded portion here. This sentence is in the original interview, right between the quoted parts:
We expect to see considerable growth in digital content, such as game download services, avatar items and the like.
Content focused response. No talk of the NETWORK requiring a fee. No indication that he's talking about anything that wouldn't be title specific. This could include a fee for dedicated servers as an option above free, non-dedicated servers. It could indicate paying to get a God button. It seems reasonable to conclude this may mean the use of alternate streams of revenue to pay for the online services INSTEAD of direct monthly fees. There's nothing there to forcefully conclude that "PSN Gold" is a "sooner or later" affair.
My main beef is with the first graf of the article. They _did_ use the monthly fees term, but a closer reading of the interview's actual statements does NOT indicate these fees are for the whole PSN or that it's a "sooner rather than later" issue. In fact, he's indicating that there are several options to reduce the follow-on operational costs of a title. ONE is subscriptions, and those subscriptions seem to have been left in the title domain, not the whole network. Just because they have it on the table shouldn't immediately validate the assumption that fees are a done deal, as the first paragraph seems to strongly argue.
Time will tell, certainly. I just don't think this language predicts a PSN Gold Membership level anytime in the next year or two. And no matter what, at least streaming Netflix will most likely always be free on PSN. Natch.