Well in a lot of Dan's shows they aren't necessarily resolved at the end(f.e. Drake and Josh, Victorious, Zoey 101, etc). I guess he commented one time on the iTTK funfacts talking about how it is a series and not a movie so not everything will be answered or resolved. Actually, in a way it was resolved. The conflict was that Spencer couldn't control his pranking, and after his classmates visited him he learned not to prank people anymore since it can get people mad.
Will the Sam crush be mentioned again? As a partial Spam shipper I would hope so, but it is possible that it could be ignored. Even if there isn't a storyline I can see it being briefly brought up again. You never know with Dan, he brings back a lot of random stuff. Like I never expected the iSpace Out freakout to be mentioned again, Melanie, the prisoners that escaped in iTTK, or the "hate the word panties"/I ♥ Vegas panties joke. He could very likely bring it up again for more humor. Being the hopeful and overly optimistic shipper I am, I hope it gets a storyline. I can dream if I'd like to.
It's a pet peeve of mine when people quote a quote over and over again. Yeah, I have to be weird and all. xD I'm not saying to get into arguements, but IF you get into arguements don't bother quoting. We can assume you're talking to the person above you and if you are not, just type in the person's username that you are talking to. Or edit the quote so it only contains the last statement and not the whole conversation. Ok sorry, the pathetic rant is over.