For those that don't know, the roster for this mode is as follows:
Alberto Del Rio
Andre the Giant
Big John Studd
Big Show (Retro)
Bret 'The Hitman' Hart
Brock Lesnar (Retro)
Chris Jericho (Retro)
‘Hollywood’ Hulk Hogan
John Cena (Retro)
King Kong Bundy
‘Macho Man’ Randy Savage
Ric Flair (Retro)
Ricky The Dragon Steamboat
Shawn Michaels (Retro)
‘Stone Cold’ Steve Austin
The Million Dollar Man Ted DiBiase
The Rock (Retro)
Triple H (Retro)
Right off the bat, there are some really fun inclusions in this roster. Yokozuna, who had long been cited by developers as a problem character to implement because of unique size, is now included, and this allows for some fun possibilities with him in the mode. It's also nice to see a few retro picks like Big John Studd and Ricky Steamboat, and this means we'll get to see the epic Wrestlemania III match between Savage and Steamboat, which is really cool. The most likely match for Big John Studd is his Wrestlemania I encounter with Andre the Giant, and it makes a lot more sense when the trailer shows Bobby "The Brain" Heenan in the game as well (he was Andre's manager at the time).
Another good addition is King Kong Bundy, and this makes sense since his Wrestlemania II main event steel cage match against Hulk Hogan seems like a natural fit for the mode. The only other logical addition for a Bundy 'Mania match is his Wrestlemania XI bout against The Undertaker, but I could see that match being one of the "extras" in the mode, as it was essentially a Taker squash match.
The inclusion of Miss Elizabeth -- a surprise, to be honest -- as well as Randy Savage, Hogan, Ted Dibiase and Andre means that there will be the Wrestlemania IV main event of Savage vs. Dibiase. The trailer shows the iconic shot of Savage hoisting Elizabeth and the belt over his shoulder with Hogan standing by their side. It's one of those iconic moments that wouldn't have made any sense without Elizabeth being there, so it's cool that they've been able to fully realize this particular moment.
It's also interesting to see Razor Ramon (Scott Hall) included in the game, which he had alluded to in a recent Twitter post. This opens up one obvious match: the ladder match between himself and Shawn Michaels at Wrestlemania X. This was the first time that a ladder match had really been sold properly to a mainstream audience, and the fight still holds up today since both guys were such tremendous workers. The match also makes sense since Diesel is in the mode, and he was in Michaels' corner during the contest. It's hard to say where else they'll use Ramon in the mode, as his few other 'Mania matches involve lower-card talent that won't likely be included. In fact, the only other one would probably be his Wrestlemania X8 contest against Stone Cold.
As for other matches, Wrestlemania 21 seems ripe for this mode, as you've got Taker vs. Randy Orton, which will likely be included, as well as the main event of Batista vs. Triple H (w/ Ric Flair). The co-main event will also likely be included, as it was John Cena vs. JBL, who has also found his way into the mode. Wrestlemania XXVII also provides a few likely possibilities, with Edge vs. Alberto Del Rio, Randy Orton vs. CM Punk and The Miz vs. John Cena.
Wrestlemania 23 has a couple of likely matches, with title fights between Taker and Batista as well as Shawn Michaels and John Cena. Big Show could make an appearance with his Wrestlemania XXV match where he and Edge jobbed out to John Cena in a triple-threat match for the World Heavyweight Championship. Wrestlemania XXVIII has a couple of options, as CM Punk faced Chris Jericho and Kane went up against Randy Orton.
A couple of the big boys in the mode -- Brock Lesnar and Goldberg -- have only a couple of possibilities, but Lesnar's Wrestlemania 29 fight against Triple H (with Paul Heyman and Shawn Michaels in the corners) might the most likely. Since Kurt Angle won't be in the mode, they can't use Lesnar's mania match against him, but Goldberg vs. Lesnar from the very next year seems pretty obvious.
There are plenty of other possibilities, and I'd recommend you check out this article to explore every possible match that they could include based on the announced roster. I do find it odd that they wouldn't leverage the current talent that could fill out some of the matches (Ryback, Daniel Bryan, Sheamus), as it would allow for many more possibilities for the last 10 or so Wrestlemania events. Maybe they will do that for some of the "extra" matches, but it's hard to say. With the roster they have picked, it seems like they are focusing on major matches from each 'Mania.
Either way, the mode looks like it could be very promising.