If RAY would lead to having RULES OF NATURE in the soundtrack then yes please include it

Methinks REX would be better, even though RAY looks better. Simply because Metal Gear Solid was actually on a Nintendo System, and RAY wasnt (Discounting Brawl that is). But thats me... Personally though, i think a Gekko would be badass, and since they are already smaller than REX and RAY, they'd still look completely natural resized.

Heck, combine all 3 together, and theres your perfect mecha character!

A Gekko would only be okay if every taunt was the MOOOOOO

Well thats pretty much the only sound they make anyway

Who's Harry and where's he from?

Chrom and Lucina shouldn't be different characters. They're completely interchangeable. One could easily just replace the model of the other and it would be fine.

That's not as likely as you think, consider this.
Smash Brothers game have been known to focus on the generation before the system it's released on (Examples: Ness was almost replaced by Lucas in Melee due to Earthbound 64, Luigi's Mansion and Delfino Plaza were stages in Brawl, Toon Link replaced Young Link in Brawl as there was no Young Link in any GameCube games, etc.)
Now with that in mind, we can expect the new Smash to have content mostly from the Wii and DS than the Wii U and 3DS. Of course, there are several exceptions such as the Garden of Hope and Gerudo Valley stages, as there were in Brawl. The Animal Crossing franchise is a great example, as the stage and Villager are based off of City Folk rather than New Leaf.

So since there were two "Toon Zelda" games on the DS, it would make more sense to see Toon Link come back. That and since Toon Link was the most requested Zelda character for Brawl, it would be pointless to add him in and then just cut him again.

Okay countering time:
Metal Gear Ray
- Metal Gear Ray was only in one Metal Gear Solid Game. It's had other appearances but only as cameos, so there it has no real significance.
- Metal Gear is a third-party franchise. There is no demand for Metal Gear Ray.
Ridley
- Ridley is in every Metroid Game and has been in every Smash game.
- Metroid is a first-party franchise. Ridley is second most requested newcomer (Behind K. Rool).
Harry is the main character from a Virtual Boy title named Teleroboxer.

Also how are Chrom and Lucina completely interchangeable? They have entirely different body types.

Congrats on missing his entire point

I think Harry would be better replaced with Balloon Fighter.
Before you say "BUT VILLAGER HAD TEH BALLOONS" Villager also had teh boxing gloves, and Little Mac is on your roster. Before you say "WELL ITS BECAUSE THATS ALL BALLOON FIGHTER HAZ LITTLE MAC IS DIFFERENT" what else does Little Mac haz besides boxing?

No I got his point, it's just that he should have used a character that made more sense and has more similarities to Ridley. Like Petey Piranha or King K. Rool.

What?

You use the most ridiculous example to make the opposing argument look as silly as possible

Dumb Internet Arguing 101

Perhaps he meant in a popularly requested sense.
Either way I'm keen eye that Dixie will make it first before K. Rool.

Hey, what the hell? I just realized people are arguing that Ridley can't be in because of his stage cameo, but the SAME argument is being ignored for Toon Link!

And here's a attempt at a roster:

BUT VIRTUAL BOY SUCKED
Assuming that goes with the whole 'history' thing behind ROB, right?

Maybe not model wise, but I'm sure it wouldn't be too difficult to remap their animations.
Character/moveset wise, I can't really see them being any different, besides Lucina being a bit faster if they were separate.

IMO, it's like saying Ike and Greil should be both be characters.

No it's not. The Conductor Link from Spirit Tracks is someone from 100 years after Toon Link establishes Hyrule with Tetra.