khspartan, you have no idea how much I want Naminé to be a vessel. It would make a lot of sense in my head (though I'd want them to save her, of course), but I won't derail the thread with talk of that. And I did state reasons why I thought it could happen in some thread here a few years ago, I think.
And technically... I don't think that was actually Naminé in Sora's dream. Rather, I think it was Xion the whole time, and Sora was just seeing her as Naminé at first.
However, there definitely is a deep connection between the two. Aside from the obvious, Naminé showed up in the Datascape in Re:Coded. And when asked how there was a Data Roxas, Nomura stated that since there was a Data Sora there had to be one of Roxas, as they make up one existence. However, there was a Data Naminé existing without a Data Kairi: probably because she is also tied to Sora's existence.
Also, this reminds me of something I've always wondered: why couldn't Naminé have returned to Sora to give him his memories back? I mean, she had all the memories he needed, and she was somewhat from him, anyway (not to mention obsessed with him). I would have liked that better, honestly, because then she would have truly made up for what she'd done, instead of screwing other people over and making them pay the price instead (if it had happened with Naminé making the sacrifice, I probably honestly wouldn't hate her so much, and they would have saved her eventually, anyway), but alas.
Anyway, here's hoping this all gets sorted out someday...