I haven't really read anything with Miles Morales, so I'm not saying yes because he's a character that I really love or relate to or anything (Although I have read that he was really an attempt by Marvel to create some cultural diversity, and to just create a black superhero. To get people talking. It did make the news, didn't it?), but I think that Ultimate Peter can stay dead. I used to love the series, but I stopped reading at about, I don't know, issue #30 or so (But I have picked up issues here and there since then.). But I loved the first year or so of the book. Bendis was a real breath of fresh air back then. But, really, the reason why I think that Ultimate Peter should stay dead is because, unlike in the Marvel Universe, the Ultimate universe can have some real lasting change/and or progression. Yeah, if he died in the regular 616 universe, we know that he would just come back in the (Probably near.) future, but he can stay dead in the Ultimate universe, and someone else can take over for him. The status quo doesn't have to be restored, and it won't be subject to executive meddling. Really, if Peter came back, it would BE just like the 616 universe where we know that nothing can really change for good, and that anything of permanence will just be reversed. I don't think that his death was so great, or so classic, but I do think that it will be a bold move to keep him dead. Otherwise, the Ultimate Universe will be just like the 616. Actually, that might be a good reason to end the Ultimate Universe. It probably has a continuity all it's own at this point, and if it keeps going, then it can get just as jumbled and convoluted as Marvel's and DC's. So, yes, I say keep him dead, but for some reason, I have a bad feeling that he's going to come back someday.