I agree. On one hand, I am
extremely happy that, after so many years, we
finally get to see Sakura's parents. I've always felt that that was one of the biggest weak points with Sakura's character. The fact that she doesn't have any unique family powers or that she didn't go through some horrible traumatizing incident in her past never really bothered me. In fact, that was what helped endear her to me and it also made her stand out from the rest of Team 7. However, the fact that we knew next to nothing about the main heroine's background just seemed weak, so I am very glad that this issue is finally being adressed.
On the other hand, I find it hard to believe that, out of 500+ chapters, Kishi couldn't some way to introduce her parents. Hell, it didn't even have to be a long complicated family arc, just a few cameo's here and there. Then again, maybe the point of showing us Sakura's parents is solely to introduce some romantic tension, i.e. as a freudian excuse for Sakura's behaviour towards Naruto in part 1 and why she may have developed strong feelings for him throughout part 2.
I also agree about them looking signiticantly older than some of the other rookies parents. Who knows, maybe Sakura isn't an only child. Maybe she has siblings. Like an older sister or an older brother. Be still, my fantard heart!
You can still see that Mebuki and Sakura are mother and daughter though. If you look at the sketch, it's pretty clear that they both have the same body type and facial shape. I'ts just that Mebuki seems older and "harsher", if you know what I mean. But like you said, it could very well be due to bad image quality.
Well I still stand by prediction. Just swap the genders and you're good to go.

For Sakura's Mom's hair, I could see why Ino persuaded Sakura to display her forehead.
As for that Motion Comic that has to do with the two Kurama's fighting, I have a theory about that. Maybe that masked man isn't Tobi but either a redheaded clone of Naruto or that version of Naruto where he is shirtless and has that arm band similar to Sasuke's during the Chunin exam (probably the AU equivelent of Naruto). The jutsu might be a combination of Ninjutsu and Genjutsu (or Ningenjutsu just to be creative (I would think since there's such a thing as Nintaijutsu there'd not only be Ningenjutsu but Gentaijutsu as well (probably a system of primary Jutsu classification (Ninjutsu, Genjutsu and Taijutsu) and secondary Jutsu classification (Ningenjutsu, Gentaijutsu and Nintaijutsu)))) that affects the entire Leaf Village. That would explain why Tobi is in his old Akatsuki outfit instead of his current war gear.
As for the question of whether Sakura's parents are a byproduct of the Genjutsu in question or the real deal, I think this is how it will go. Sakura's parents probably didn't participate in the war so they stayed back at the village along with the other civilians. The movie's villain sets up the Genjutsu around the village which effects everyone (it either creates alternate versions of characters out of thin air or drastically changes their personalities forcefully (with the exception of Sasuke because I'd doubt he'd return to the village that easily if at all)), except for Sakura's parents. The reason being that either both are from the Haruno Clan and therefore immune to Genjutsu or one the mother is the actual Haruno and grants her husband Genjutsu immunity (which I hope is more likely because I like the idea that Sakura's dad had his surname changed when he married his wife better then the thought that Sakura's folks are blood related (I don't care how distantly related they could be, it's still weird and creepy to me) and if Sasuke's parents are distantly related, the less similarities with that Uchiha bastard has with Sakura the better it is for us since then Sasusaku fans have less ammo to make bullsh** theories that those two are destined together or something stupid like that. They then proceed to help out Naruto, Sakura, Minato and Kushina break the Genjutsu, free the Hidden Leaf Village and then defeat whoever is behind this dastardly evil plot.
What do you guys think about my latest theory? Feel free to respond to this post to either add to this theory, fix some stuff that doesn't go together too well or just debate the unlikelihood of this ever happening. Though if you ask me, I would consider this theory to be highly possible to a certain extent, it may not be 100% accurate to the actual plot when the movie finally comes out, but some aspects might be similar considering what information we've been shown. As for the movie's continuity itself, I do genuinely hope that this movie is considered canon like how Strong World is canon in One Piece continuity. That way if Kishi doesn't make a chapter introducing Sakura's parents, he could make up for it by actually having the movie be canon. Though I'd still think a chapter where they at the very least introduce Sakura's folks in a flashback telling her to be careful as she departs for the Allied Shinobi Forces HQ in the Land of Lightning.
That's my whole take on the issue about when and where Sakura's parents should make their first debuts.
Terrorking, I would actually prefer that Sakura has a hidden power that she hasn't unlocked yet. Of all the characters introduced in Naruto, each of them has a unique ability that's one of their defining traits. And also, Naruto in itself is a battle manga, so a lot of the characters are often defined by their special fighting abilities.
As K9 says, it would be interesting if Sakura's parents had the special ability to be immune to Genjutsu. To further expand on K9's theory, I could see them somehow interfering with Tobi's genjutsu. I could see it going like this:
Tobi puts NS in the genjutsu, Sakura's parents discover them and Tobi retreats, because the Genjutsu takes up massive amounts of chakra and his chakra supply is almost zero. Thus he retreats because he doesn't have enough energy to spare to fight even a low-chuunin level ninja. But not before he smugly declares that the genjutsu is unbreakable and he can kidnap Naruto anytime once he recovers.
Kizashi and Mebuki then starts getting to work to interfere with the genjutsu by inserting themselves in the genjutsu while keeping their personalities intact. Then they both become the main supporting characters helping Sakura learn to unlock her secret ability.