Here are just some of the reasons I believe Seddie will happen (these are more facts than my dreams). Also, the list is only a short sampling of many reasons, which you should feel free to add on. If I missed any really important points, please tell me so I may add them.
If you do not ship Seddie, please be kind in your comments, I don't mind if you don't agree, as long as you are pleasant about it.
Keep in mind that I can come up with tons of other reasons why they will/should end up together, this is just my list of some more factual points. But, of course there are tons of other reasons. Please share your own thoughts!
Sam and Freddie will get together. Sure, I'm saying this because I'm a huge Seddie fan, but there's also logic behind it. Here are just several of my many thoughts behind this:
1. Why would they build this episode up so much, exclaiming how "Sam's in love" and that "iCarly will never be the same" if in part 2, Freddie is just like, "sorry, I still love Carly."??? If that was going to happen, they certainly wouldn't have built iOMG up so much.
2. Carly said it herself, this is the first time Sam's liked anyone who's not disgusting, heavily tattooed, or on parole. Carly also gave Sam a speech about going for it, and Freddie told her to let out her feelings (which she did :D). So, if Sam gets her heart broken, it just shows that all of the efforts her friends put into her being happy, were just ignored.
3. This episode was built up so much, that Nick and the cast and crew, especially Jennette and Dan, made it quite clear that Seddie was going to happen. Yes, there was an amazing Seddie kiss, but there were obviously hints that there would be much more.
4. There will be a part 2. I know it's not until July or so, but there is a part 2. Why would they have a part 2 if they just wanted Freddie to reject Sam? They could just have that explained in the next episode. If Freddie does reject Sam in part 2, it will probably be out of shock, and they will get together later in part 2. There's no reason for a part 2 if Freddie completely hates Sam/doesn't like her romantically. In fact, all of the buildup to their relationship, especially iKiss, iTTK, and iOMG, would be quite pointless. I doubt Nickelodeon would waste their money making so many episodes that build up to Seddie if it's never going to happen. Sure, there was iSYL, in which Freddie and Carly got together (ewww), but it was more of a Seddie turning point, because when Sam pointed out to Freddie that Carly just liked his hero complex, he believed her, and dumped Carly, who he had a crush on since he was little. This proved that Freddie really does listen to Sam, and that his feelings for Carly are fading. Plus, Carly never took him back after his hero complex was gone.
5. If Freddie rejects Sam, then things will become very awkward. Such an event will permanently come between their friendship, and iCarly would never be the same because Carly's two best friends would barely speak. No one wants to watch 30 min of awkwardness every show. Sure, there may be awkwardness at first because of their kiss, but in the end, they will get together. Plus, Sam and Freddie may still tease each other, so we wouldn't watch 30 min of boring and predictableness, instead we would watch an ever-evolving relationship, that will have ups and downs, but ultimately will be strong. I mean, can you imagine watching 30 min of Sam and Freddie acting awkward every new episode? I can't, that would just be too annoying.
Anyway, I don't know if you read any of that, or if it made sense to you, but the bottom line is that SEDDIE WILL PREVAIL!!!