Hmmm, I hear more and more often about people organizing pickup raids to places like Molten Core. But I personally have never seen such a pickup raid. That is probably because I usually play on the Horde side, and Horde is just not as numerous as Alliance on a PvE server. The more people there are in total, the more likely is it to get a 40-man pickup raid going.
The only thing I've ever seen on offer on my server was a guild offering spots in their MC raid, but if you received an epic you would have to pay them 300 gold. That didn't look attractive to me, you would have to both pay and work for the epic, effectively paying it twice. And of course the guild in question had first pick rights on everything.
The problem with pickup raids, from my point of view, is the relatively low chance of receiving an epic, and the relatively large chance of receiving just a large repair bill. But of course the better the raid succeeds, the less of a problem that is. So if you have an alt, and your guild doesn't equip alts, you might want to run a MC raid with other people's alts. If everybody is an experienced raider, MC is possible even in a pickup group with strangers in tier 0 gear.
Did you ever participate in such a pickup raid? Care to share your experiences? How was loot distributed? Did people fight about loot, or was it a very civilized affair? How was leadership organized, and were there discussions on strategy?