Why real-time RSS is a big deal for big payloads, too

I'm very much interested in emerging Web publishing ping systems like Google's PubSubHubBub and Dave Winer's rssCloud. I call these systems "real-time RSS" for short, since they basically allow syndicated content ("RSS") to be delivered at Twitter speeds ("real-time").

I've noticed a focus on using these systems to replicate Twitter, but think the opportunity for publishing bigger-than-Twitter content is just as exciting.

Why I'm kind of obsessed with this:

1. As an RSS consumer, fat-content real-time RSS could improve my ability to read blogs. I read hundreds of feeds for my day job, via Google Reader, the best RSS aggregator available. Some of the most essential feeds are updated within Reader only sporadically, hours after the originating feeds have updated, literally making me worse at my job (timely blogging). Real-time RSS systems promise to solve this problem (Google Reader is already starting to implement these systems.)
2. As an RSS publisher they could improve my ability to reach readers. I don't have a technical role at the blogging company I work for, but I've advocated real-time RSS as a way to reach our readers faster, and to stay competitive with other publishers. Frankly, I'd love to see our feeds updating fast in Google Reader, because they come pretty slow at the moment, in giant clumps covering hours, and I don't want other sites gaining a big lead.
   
3. As a technology observer, I'm curious to see whether the split between Twitter-like, 140-character-or-less implementations of real-time RSS and "fatter" uses of the systems can be resolved in an elegant and constructive way. "Let's just duplicate Twitter" seems way too constrictive a way to view these systems from where I sit; on the other hand, the less ambitious approaches are the ones that tend to be simpler, and thus "win."