There's suttle hints within FFX-2 that suggest this.

1. Close to the end of the game Shinra mentions the fact that it's possible to drain the Farplane for energy (MAKO), and Yuna remarks that one day Spira might resemble Zanarkand.

EDIT: (Shinra divulges this when you return to the airship after venturing into the 100 level Bevelle dungeon)

1 1/2. Shinra is a genius and made the (MAKO) discovery, he could be the origional President of Shinra.

2. I haven't looked very hard but it seems that FFX-2 map and FF7 are identical... i'll let someone else check this out.

EDIT: After further research this has already been discussed in great detail:

http://forums.ffshrine.org/showthread.php?s=&threadid=11113

huh.... =____= ?
it's there? never noticed that before.... And I don't think I get the first hint though.... I mean... Never mind I'm sleepy and can't think of a thing now, but I really can't pick up the point from your first hint.
And for the map thing... I actually went to compare them online but I think all the maps look alike.... O__O FF7's map look like FF9's too... Ahh well I don't know, or you meant something else when said they are identical?:eek:

By the way Your icon is not Aries, just to tell you that incase you didn't know, it's Yuna~ Just compare it with my icon and you can tell :lol

3. If you solve Rin's mystery and pin Rin as the culprit, Rin reveals that he is behind the machina incidents and that he and his people have been researching ways to extract energy from the Farplane.

Oh yeah I remember that part! this makes sense, I'm thinking about the first one now... Wait... Let me think.. Maybe I'll get it tomorrow, after a sweet and nice sleep. =P

Off topic reply to kawiridle.

It can go either way, several Final Fantasy characters resemble eachother. Plus the fact "Aeris New" picture has ribbons in her hair, just like Aeris in FF7. Also the pony tail.

Eye colour automaticly devoids it being Yuna--Aeris' eyes in FF7 are light blue, in the picture they are... well they arn't light blue but close enough to warrant a match.

Either way, she's beautiful. Only reason for it being my Avatar.

Yeah, there also a # of similiarities I posted in the FFX section between FF7 and FF10....

You know, I'm not sure...its POSSIBLE, nothing substantial yet, but it wouldn't surprise me.

Wow. I'd never even thought of this. It would be so fitting too, what with Advents Children on the horizon. Methinks I must re-play X-2 and find out.

Off topic, Shic, where did you find the picture for your avatar? I've been trying to find the "new aeris" pic.

That would be really awesome if it was but I have a few questions. 1.) It would take a VERY VERY long time to have the world of 10 change into the world of 7 and if thats the case, has Shinra been around that long? Does anyone know if it says how long Shinra has been around? I guess I only have one question, i thought i had more. Does anyone know if there is anything in ff10 or 10-2 that wasn't in 7 and couldn't have been invented and then not have beeen invented (for example, space travel)?

Hmm, it's possible. Shinra is definately not the President Shinra in FF7, but his family bloodline could make it his grandson or something. Seems like a fairly substantial theory, very interesting. I'm just up to Chapter 3 on the game but I'll check some things out...cause there's still the matter of the Cetra and the Promised Land to be explained.

I think that all the Final Fantasys are on the same planet at different intervals of time like on the Time Machine movie.

I think that all the Final Fantasys are on the same planet at different intervals of time like on the Time Machine movie. But yeah, doesn't it say that the Ancients are well....Ancient? I mean, that must be a huge time period. But ya never know cause in that movie he goes VERY far into the future and you would think that technology would be superbly awesome but in the movie the technology actually regresses as does it in 10, going from big Metropolis' to little villages at Hawaii cloned islands.

well , is quite possible , but then again , maybe Square Enix is trying pull our legs here.C'mon , they name the guy of all names Shinra.Then they have him talking about how he is going to extract energy from life.What do you think?

but like i said there is a possibility,
if FFVII and FFX-2's world are the same , then the same goes for the Lifestream and the Farplane. maybe the similiraties is only in concept , (dead people go to these two places).Then we have the materia's and the dressphere .Both of them shares the same concept which is The memories of dead people are stored within them.

if both worlds are the same , wha happen to the ruins of let say bevelle or zanarakand or luca?yes ,lots of thins can happen in 1000 years .but eventhough is has been 1000 years , you can still the ruins in Besaid and Zanarkand,

I've read an interview with a programmer about this problem, and my personal impression was that seemingly, the programmers' themselves don't seem to have settled on one clear idea whether FFX-2 should really be a prequel to FFVII, and how the two would really work together. The interviewed guy talked about what was his own idea about Shinra and the link, but no where was said that there was an official theory, or even an official timeline.

I suppose that all games are more or less meant as stand-alones, unless really marked as sequels, of course. I'd not try too hard to find a way to fit everything into one timeline.

u guys said it .... the whole thing would take generations to do ... it said so in the game .... and because of that ... Yuna got a bit upset 'cos she wouldn't be there to see it -> making Brother upset with Shinra who dared to upset Yuna lol ..... i noticed that too .... and i posted some very long posts in great details about the idea in another forums ... sadly, their reactions to the idea were extremely disappointed ... though i said quite clearly at the beginning that it was only a theory but it seems that those guys don't even understand the concept behind making theories in FFs ....

to misao ... do you still have the link to that interview or do you have it on ur comp. ??.... i'm really interested in taking a look at it ....