@Hericks  
As cool as that sounds, I think going as long as the Simpsons would be overkill. But up to say, Season 13 would have been nice.
 
@TheKman100  
Then why can’t they just focus on the newer characters or the older ones whose screentime hasn’t been significantly high like any of the princesses minus Luna. Also, I liked A Matter of Principals. Mainly due to being on Starlight’s side.
 
@Hericks  
Now we’re talking! All the more reasons towards why this show still has untapped potential!

@TheKman100  
Yeah, if they were going to keep going, they would have to start putting more focus on secondary and background characters, although the change in status of the main 6 does open up potential for episodes. I won’t say any more about that to avoid spoilers.  
Plus they could have expanded more on the other nations, seeing more of the other creatures of the world. Like, for example, they could have had the main 6 go to the nation of the diamond dogs. I mean, they just show up in season one for a single episode, and are then never heard from again? What the heck!? I wanted my diamond dog episode darnit!
 
But, yeah, there were many ways they could have expanded.
 
 
Actually, I wouldn’t have minded if they just followed a new cast in the next generation, and having it being in the same world, and getting to see the original cast pop up every now and then. That could have been nice…

@Hericks  
Not to mention the plot-specific character derailment. With how much these characters have grown, I’m afraid a tenth season would bring us more episodes like “Yakity-Sax”, “A Matter of Principals” and “2, 4, 6, Greaaat!”.

@Red-Supernova  
In all honesty, they probably could have had this show go on as long as the Simsons if they wanted. But they probably didn’t want to pay the staff with the increasing raises.

If only the higher ups overlooking this show realized that this show still has the potential to put out gasp more seasons. (Yes, I’m still sore about that.)

“Well, you don’t have to meet him onscreen.”
 
“…what are you doing here, Pinkie Pie?”

@Wiimeiser  
Well, for me it doesn’t matter, since I’ve already watched the finale, But I’d try to avoid posting any details about the final episodes until at least a week after it has officially aired, and even then still use the spoiler tags.  
I just know how much I hate spoilers, so I try to avoid giving any kind of spoiler myself.

@Hericks  
The synopsis has been officially released, so not going into detail shouldn’t be too much of a problem, right?

@Wiimeiser  
Shhh, spoilers…

And this is the last true filler episode, as Episode 23 completes a previous story arc.

@Mirror Star  
Can’t count out the comic series, and I’m sure there are already fanfics out there  
And there’s also the manga now that they may make an appearance in.

That’s where we fans come in. You can have adventures forever in fan works.

There’s the comics and fanfiction left.