Literally just got off the phone with 3 Sprint Reps:

1 & 2 who were in Kansas both said the release date was May 9. In fact, the first woman I spoke to was skimming her notes and said "That's odd, it says it should have been out today but it's not." She paused and asked a counterpart and got the May 9 date.

Woman #3 was in telesales and barely spoke english. She was more concerned about selling me an "upgrade" to anything out there that wasn't a Blackberry and told me the Curve would be out in mid-June.

Take it for what it's worth....