Feld thinks branded RSS aggregators are gonna be a Big Deal.
The value prop to content owners is clear - ownership of customers. But the value prop to consumers, I think, is kind of murky. Why would I choose XYZcorp's branded RSS aggregator over, say, a generic one, like Bloglines? Presumably, the generic one will offer me greater benefits, because it will be, by definition, ad-free.
So, to compensate, I think branded RSS readers will have to offer consumers something else that's cool. I can't figure out what this might be.
The next problem with this model is that all branded RSS readers will be essentially substitutes for one another - take away the marketingware, and you've just got a simple RSS aggregator. Without any kind of meaningful differentiator, it's difficult to agree that there really is a market here - just a bunch of commodities wrapped around a brand. Now, P&G can make this model work because they own shelf space at retailers. But switching costs on the Net are much, much lower.
The other possibility is that branded RSS feeds essentially become fixed distribution channels for viral marketing - you hit a corporate site, and it has a branded RSS aggregator which grabs all the buzz on the net about it's products. This model has a much better value equation, and I think it's probably what Feld is referring to.
Of course, there are still several problems with even this model. The most obvious is that marketers have little/no control over this channel, which is something most marketers will, I think, resist. The second is that tuning relevance within the feed may be tricky. Third, I think branded RSS will meet with a large amount of consumer skepticism - RSS is cool because it's neither owned nor monetized, and I think more people know this than we think.