This SPOILERS for The Flash Annual #2 and Heroes in Crisis #5
Wally West is dead, and no one seems to know why in DC Comics. The third and, arguably, best version of The Flash was revealed to have been one of the dead in Heroes in Crisis #1, the first issue of Tom King and Clay Mann’s event miniseries focusing on a mass murder of superheroes. Many fell at the supposed safe haven of Sanctuary, but none were more shocking than Wally West.
Wally died barely two years after he returned to DC continuity in DC Universe: Rebirth #1. This, combined with the fact that Wally’s story was left very much unfinished in the mainline Flash comics, made his death seem very bizarre. Even stranger was the fact that DC didn’t acknowledge Wally's death (except out of the pages of Heroes in Crisis). Now, the wider DC Universe is finally reacting to Wally’s death... and those reactions may give some clues to his inevitable resurrection, even if the typical method of a Flash's 'rebirth' is out.
Since Heroes in Crisis #1, The Flash comic has been silent about Barry's grief over the murder of his original sidekick. The Flash #63 and Flash Annual #2 finally have Barry Allen express his feelings surrounding Wally's death, and goes the extra step of revealing what took so long. It turns out that the delay has been because The Flash series hadn't actually caught up to the present day of Heroes in Crisis. The second Barry finds out Wally is gone, he loses it, immediately searching for Wally in the Speed Force. Sadly, Wally is nowhere to be found.
For decades, The Speed Force has been DC Comics' catch-all to explain missing or presumed dead speedsters. Barry, Wally, Jay Garrick and even most recently Bart Allen have all been trapped in the Speed Force when they were thought dead by the rest of the world. With Heroes in Crisis though, Wally won't be so lucky to just run out of the Speed Force and come back to life. When Wally was killed at Sanctuary, he actually, biologically died. Yet that still might not rule his return out completely.
The evidence for this won't be found in The Flash but Heroes in Crisis itself. During Heroes in Crisis #5 the body of Wally and all the other victims are finally examined. This is when the suspected murderer Booster Gold makes a huge discovery: Wally's body is five days older than it should be, based on the current timeline. This suggests two possibilities: the less likely one is that this is a different Wally West from another universe. The far more likely one? A time traveler is somehow involved in the murder of these superheroes. While tragic, that may be some very good news for Wally's potential resurrection.
Booster Gold is desperate to clear his name of the Sanctuary murders even though everyone but Blue Beetle has already been convinced of his guilt. One of Booster's primary powers is that of time travel, meaning it's not much of a leap to assume Booster will travel in between those five missing days of Wally's life, and perhaps try to save the younger Flash (and everyone else) from their gruesome fate. Since Wally is no stranger to time travel either, the chances of him escaping that fate are higher than most.
There's still a lot of secrets left to be uncovered with Heroes in Crisis, not the least of which is who is the actual murderer. Booster still could be inadvertently responsible, but him truly being the culprit is seeming more and more far-fetched. Interestingly The Flash Annual #2 has introduced a mysterious new villain from the future who sparks blue lightning (and has a grudge against The Flash Family). This mysterious figure, who may be a "new" Savitar, probably isn't the killer as he (or she) only has a grudge against The Flashes--but it's possible. Anyone who can time travel in the DC Universe should be looked at with suspicion now that Booster's revelation has changed the game.
Even if the new information doesn't get us closer to the killer, it does provide some hope for Wally's return. Death has and always will be a revolving door in superhero comics. With characters like Poison Ivy and Roy Harper dead, it seems impossible for DC Comics to permanently lose them all.