TechNews points to an email from Valve's Doug Lombardi received by the team at Mod-HQ which confirmed Valve hoped to have Half-Life 2: Aftermath and Half-Life 2: Platinum shipping at the end of the April, on the 24th. I hope everyone remembers the original Half-Life 2 release fiasco and is at least sitting at their computers with crossed fingers.

It's confirmed! Half-Life 2: Aftermath Coming April 24 [TechNews]
*Updated* HL2: Platinum & Aftermath Launch on April 24th [ModHQ]