I discovered this morning that I'd been having technical problems grabbing PodCastle and PseudoPod RSS feeds over the last month; this seems to be fixed now, but in my troubleshooting this morning, I discovered that all the links to MP3's (at least, all the ones I tried) are failing and going to a 404 page.
I can't imagine this is something on my end, especially having just confirmed it from work, but I'm always open to the possibility.
Anyway, on the off chance that this has slipped unnoticed through the cracks, I thought I'd mention it.