Andrew House gave a bit more substantial answer in a recent Q&A on the UK PlayStation site. When asked outright, "Will PlayStation Network become a paying service?", House responded, "Kaz Hirai stated a few months ago that we were looking at a premium service to sit alongside the current free service and that objective has not changed. You'll learn more about it very soon."
He went on to console potentially upset readers with the knowledge that "the current PSN as you know it will remain a free service." That said, it seems like times are a-changin' for Sony's online network, and some (if not all) of the claims in our recent report on a "PSN+" service may come to pass in the not so distant future (cross-game chat, anyone?). If we were bettin' folks, we'd bet that not so distant future will start around the time of E3.