I mostly stay away from making predictions.  First, too many people already don't and second, this is the WWE and as they say in racing: "any horse on any given day ...".  But since this is Wrestlemania and to quote JR, "the most grandiose stage", I thought I'd throw my Stetson into the ring, figuratively.

Here we go:

JBL vs. Rey Mysterio: I love Rey.  Everybody loves Rey.  But there are rumors perhaps not so greatly exaggerated of JBL's imminent retirement.  If ya need to walk, WM's the place to do it.  Will the win be clean? Hell, no! Its JBL.  Fortunately, RM is one of those guys who is so over, a few losses on the Most Splendid of Stages won't hurt his career. 

Winner: JBL, by nefarious actions.

Jericho vs. the Legends: oh, h*ll, flip a coin.  One thing is sure: it won't be Jericho.

Jeff vs. Matt: Its Jeff's time.  Its that simple. He's finally on track and on a roll.  He's even more over than before, if that's possible. It would be stupid to de-rail him now.  (Not that WWE  is exempt from stupidity.  Contrarywise, oh Caterpillar.) But of the two, he's always been the more extreme by a slight margin.  With all this is his favor:

Winner: Jeff

Money in the Bank: this match always goes to the next big guy, the one who is ready to move up to better things.  Sentimentally, I'm rooting for Kane.  The guy's starting to become WWE's Chicago Cub.  But Ladder matches don't favor him and WWE is perennially idiotic about him. Punk won last year and history doesn't always repeat itself.  Kofi? Too new.  Mark Henry? Too annoying.  Finally Finlay? Way fun, but why now?  Leaving Shelton, MVP or Christian. The first two are currently in a lovely feud of their own involving the US Championship, so as much as I'd love to see MVP get the push, the probable

Winner: Christian

Diva's Battle Royal: If this were six or seven years ago and this match was about crowning Miss Wrestlemania the best bikini-boded-type pageant winner, my answer would be much different. But WWE's worked hard to move its girls away from that stereotype toward a more athletic, more respectable type of true wrestler.  I applaud that.  And I don't think they'll reverse themselves now.  If this is going to be about getting a title shot, its down to McCool or Phoenix.  The gentle patter of pins dropping during Michelle's entrances point to the latter.  Otherwise, its going to be one of the returning non-resident divas. That last is where I'll put my money.

Winner:Trish Stratus (etc)

Carlito & Primo vs. John Morrison & the Miz: Carlito & Primo are going to be amazing.  Key word: going.  They're getting closer every time out. But this is Wrestlemania and they are not quite at the level yet to walk away w/ the Unified Tag titles.

Winners: M & M, in a h*ll of a good show

Edge vs. Cena vs. Big Show: This could go two ways: predictable or quirky. The quirky way would be to have Big Show win.  It would make use of the KO he's been stumping for since he used it on the Undertaker. And it would give him a huge push. And we'd have the whole saga of inspirational love again (VG seems to be quite a muse, doesn't she?) But is BS ready for it? Predictable version: Cena finds a way to beat Edge and bring the WHC back to Raw, where it belongs, which could set up a continuing feud if Edge gets drafted. This is WWE after all.

Winner: Cena

HHH vs. RKO:  If this were any other paper view, I'd strongly lean toward RKO.  But this is Wrestlemania.  They're going to try to pretend this is the main event.  They're going to want to send the crowd home happy and satisfied, with all loose ends neatly pinned in place.   That doesn't happen if RKO wins.

Winner: HHH

HBK vs. the Undertaker: The "a-duh" match on the card in terms of who wins.  This one isn't going to be about winning.  The beauty of this match will be its quality, how it plays out.  This is going to be a clinic, the kind of show the Natural put on when he beat Sylvia, but with even more drama.  This is going to be one you watch two decades from now because it is a turbulent, raw, unbridled piece of wrestling artistry. Just sit back and enjoy the ride.

Winner: Undertaker in THE main event of the night