#4 We would have seen a dream match at Wrestlemania 22

At the time of his passing, Eddie Guerrero was considered one of the finest wrestlers on the planet. In fact, Kurt Angle called him second-best only to Shawn Michaels with him possibly outdoing even The Heartbreak Kid if he were still alive. I mention Shawn Michaels because it is relevant here.
For the longest time, Eddie was considered something of a Mexican Shawn with his good looks, supreme athleticism, and stellar in-ring work, and the WWE was planting the seeds for a dream Wrestlemania 22 match between the two men in 2006 with the feud centring around how was the better professional wrestlers.
It would have been a dream match for fans all around the world and it is just one of the many things that we never got to witness due to Eddie's heart failure.