[Kalimac]

Mhoram - I never thought I'd be saying this but it's good to remember once in a while that technically speaking NONE of this is factual. The idea of hobbits being created for this particular eventuality (though it isn't one I go for, personally) is an interesting one and isn't specifically refuted by anything Tolkien said or wrote, so why not speculate?

And Morgoth, I'm a little confused by your question. Do you mean "if the Ringbearer dies, who has the ownership rights to the Ring"? Aragorn might be the answer, but personally I'd plump for Sauron - he's the one who made the Ring and his spirit still owns it in the way it will eventually corrupt anyone whose hands it passes through. It's true that Isildur won it from Sauron, and all of those who had it afterwards only found it because it was lost, then stolen (Gollum) lost again (Bilbo) and inherited from someone who didn't know its original ownership (Frodo). If you want to be strict, the fact that Isildur never voluntarily gave up the Ring and that Gollum stole it from Smeagol would make Aragorn the person to lay a claim to it, but he never does - for obvious reasons - and the consensus is pretty much that Sauron is the only true Master of the Ring; anyone else who is in possession of it (Bilbo, Frodo, et al) is essentially racing against time, trying to somehow get rid of or get away from the Ring before its effects destroy him entirely.

So if the Ringbearer died, the Ring would not be inherited by a "new legitimate owner" because the only person/entity whose legitimate property it was, was Sauron. Instead it would pass to whoever the Ringbearer's heir was, or whoever happened to be around, depending on the circumstances. (After all, when Isildur died the Ring just slipped to the bottom of the water, and it's not like when Gandalf realized what Bilbo had found, his first thought was "Hey, this is Aragorn's property, let's see if he still wants it"). Case in point; when Sam thinks Frodo is dead, he thinks "And the council also gave him companions, so that the mission should not fail" - it never occurs to Sam to go off and hand it to Aragorn (hey, it's his responsibility now, hooray!) he only realizes that the Fellowship had been there by way of reinforcement - one of them could, at a pinch, take the Ring and become Ringbearer if the original Ringbearer were incapacitated or killed. That's exactly what Sam does, but he never thinks of himself as owning or inheriting the Ring - as indeed,neither does anyone else.

And for the record, I doubt Sam could have made it to Mount Doom on his own. I base this on the fact that he only went about a hundred feet before deciding that he couldn't do it "Not without Mr. Frodo" and turned around to go back to him BEFORE he knew that Frodo was still alive - as far as Sam was concerned, he was going to die protecting Frodo's body and then who knew what would happen. This isn't to take anything away from Sam (Frodo could never have done it by himself either) just to say that their two characters combined made success possible whereas just one of them would have collapsed before reaching the mountain.