First off, I definitely think podcasting is a fad. Unlike blogs, where you can get data from a thousand people in a day and make sense of it, podcasting requires real time to take in, and has far lower information density than a blog.
There's a temporary 'cool' factor to hearing the voices behind the words, or putting your words out there. However I believe that many people will only put up with shoddy production values in a text-based blog and now, in the early days of 'podcasts'. Eventually the 'marketplace of ears' will gravitate towards professionally qualified speakers, who will (and already do, from what I can see) dominate the podwaves. There's already an 'abandonment' issue with blogs, and I think that the abandonment rate for podcasts will be far, far higher.
Also, podcasting will never be the 'everyman' movement that blogs have the capability to be, and we shouldn't want it to be. There may indeed end up being more podcasts than there are radio stations, but the 'curve' of who gets listened to will be extra-sharp. This makes it a 'fad' in my eyes, at least.
(We shouldn't want podcasts to be the everyman movement, because it is nearly impossible to extract useful information out of them. A recorded talk show that talks about the decisions of the Supreme Court isn't searchable, indexable, hyperlinkable, or anything else that makes the web...well, the WEB.)
Anyway, I think Microsoft is doing some very cool things with their RSS support, despite my normal dislike for them. That said, I hope that Microsoft takes to heart the idea that this 'feed store' that they are creating should be able to be exposable to the network via an open protocol, that anyone can implement client or server for.
This way, I could kick back on my Mac, running NetNewsWire, and have my subscription feed be the same as when I'm sitting on my Windows box at home, or at work, running a Windows aggregator. I can subsribe from any box, and all my boxes know about it. You have the opportunity to fix the 'bookmark' problem now, before it happens all over again.
One extremely important place that this comes in, is in password-protected syndicated content. It's only a small subset now, but as pay-for site-subscription models and even subscribing to sensitive application data (like the log file aggregator mentioned at Gnomedex) become more popular, you really don't want to be putting those feeds someplace where the passwords are exposed.
Putting it all together, I actually think that Microsoft has the opportunity here to define (or work with the community to define) a good, not-Windows-specific feed storage and retrieval protocol, also opened up under a community-friendly license.
-- Morgan Schweers