We're really pretending like whoever beats Rusev is going to get a massive rub? Who has Rusev even gone over on his streak? Big E? Jack SwaggeR? lol It isn't exactly like he is tearing through the roster's top guys.
Let's be honest... Rusev in a feud with Reigns is a massive rub for RUSEV, not the other way around. Even if Reigns beats Rusev at Mania, that is the most notable thing to happen to Rusev by far.
Rusev's streak is being treated like a big deal by WWE. To the casuals, then, it's a big deal. To the kids, it's a big deal. To the guys with families who don't spend every waking moment thinking about pro wrestling, it's a big deal. The only people who don't think it's a big deal when watching Raw/Smackdown/PPV's are people who don't fit the above categories, which describes about 7% of the WWE's "Universe".
Now, let's examine the guys who Rusev has "torn through":
Jack Swagger - 1X World Heavyweight Champion, 1X ECW Champion, 1X U.S. Champion, Money in the Bank Winner, 1X FCW Champion (doesn't get as much play since it's now the NXT Championship, but I digress)
Big E - 1X Intercontinental Champion and 1X NXT Champion (remember that the NXT Championship is given a pretty big deal of currency when talked about on WWE television)
Mark Henry - "The World's Strongest Man", 1X World Heavyweight Champion, 1X ECW Champion, 1X European Champion
The Big Show - "The World's Largest Athlete", 2X WWE Champion, 2X World Heavyweight Champion, 2X WCW Champion, 1X IC Champ, 1X US Champ, 8X Tag Team Champ, 3X Hardcore Champ, Triple Crown and Grand Slam Champion
Now, you and I might know these aren't the top guys in the promotion here at the dawn of 2015. But that's because we spend an inordinate amount of time thinking/talking about this shit. To the grand majority of the folks in the stands and "watching around the world", this is a pretty decent resume. He may not be beating Alabama and Oregon here, but he's beating Baylor, TCU, and Boise State. So, his streak is a legitimate point to build on.
The real question is can Reigns beat Rusev and still "make" Rusev "look strong".
wk