No, but Whedon definitely killed him.
While we're on the topic...
Havok "died" in an explosion but his soul somehow possessed the Alex Summers of a parallel world.
Multiple Man "died" from the Legacy virus but it turns out that was just a dupe and "Madrox Prime" was walking around with amnesia. And then there's the "They Keep Killing Madrox" story...
Strong Guy died but was brought back by Layla. He came back soulless, however, and is now a Lord of Hell.
M died (Strong Guy beat the hell out of her) but was brought back.
Alex's dad Corsair was believed dead for years but actually died not too long ago. I think he's one of the few who'll stay dead, though.
Wolverine "died" in combat (but this was a Skrull) and died/went to Hell under Aaron. Would he be considered "dead" that time Nitro reduced him to a skeleton?
Oh yeah, and Captain America, the FF, Spider-Man, the X-Men, etc. all died in Secret Wars but Colossus was able to revive them (probably with some subconscious help from Dr. Doom/Beyonder). Cap died a few times in that last fight, didn't he?
But I don't think we should count these mass deaths, just like we're not counting the Infinity Gauntlet deaths/resurrections, right?