In my opinion, iCarly has jumped the shark with the Seddie arc. I am a huge fan of the show, but I'm disappointed that Dan would do something like this. It was all to get views. Everyone (and me as well) will keep watching iCarly hoping that they get back together at some point. We all took the bait. Just like when Carly and Freddie dated. They needed a fresh idea to keep people interested in watching. The Seddie thing obviously worked. If the next few episodes are as if seddie never happened, it will further prove my point.
Now on the other side, iCarly did have the arc about Sam and Freddie kissing and it further developed into them dating. So who knows something else might happen between the two. Also, think about when Carly and Freddie dated. They ended the relationship in a similar fashion saying "someday we might get back together" and that obviously didn't happen.
So yes. That's my two cents on what happened. Who knows that Dan has planned.