Dave Winer -- the father of RSS -- can't tell if the problems he's having with Apple's RSS are just the beta blues or if Apple's up to something a bit more nefarious:
Engadget quoted Jobs as saying they were using “industry standard” RSS. Even if we used terminology like that (we don’t, there’s no standards body for RSS) one company can’t on its own say it’s standard, esp when it has so many mistakes in it. It’s a fairly damaging lie...Assuming their intentions are good and they’re not trying to kill RSS, why don’t they put some of us under NDA and let us help them get the bugs out before they ship.
The ensuing comments do a pretty good job of vetting the problem and at least one of them highlights an internationalization issue with the date format used in many RSS feeds. But based on Dave's response, the diagnosis hasn't changed.