I think the 'wow' gives it away.
Well given that the list of contributors like Alan Grant, Garth Ennis, Gordon Rennie, Arthur Ranson, etc. the wow could have been for that.
I believe the plan is to run tributes from comics creators, at all levels in the industry, throughout the month so there will be a nice variety giving different perspectives on the comic. I'm not sure it'd work so well if only the famous were allowed to contribute or there was some notional line in the sand that made you worthy enough to be included.