Originally it was supposed to be early May, then it was moved to late May... so I am not too surprised.  I suspect Musk is delaying it in order to get a bigger audience.  We do know that the battery chemistry will be addressed and the thing with the "tabs" and we have, at least a hint, that the $100 per kWh barrier might be broken.... however, at the risk of repeating myself for the 132nd time:  the actual barrier of $100 or below per kWh refers to the Battery Pack cost and not to the per cell cost.  Threre is a huge difference.  I don't know if Musk is referring to the Battery Pack cost or to the per cell cost, but I suspect that this early on he is playing a little bit with the public and is in reference to the per cell cost.  That would not be a true break even point for BEVs vs ICE vehicles.  I hope I am wrong but I don't think we have reached that break even cost comparison yet re: BEVs vs ICE vehicles.  I am only guessing, but I think anyone who claims that is probably gilding the lilly at this time, but it shouldn't be too much longer.  Maybe by mid 20's ?  If Elon does make the claim that BEVs are not less expensive to own than ICE vehicles then I am sure that every naysayer on the planet will jump on that statement like a tick on a dog, like white on rice in an effort to disprove it.   Should be interesting to say the least so... stay tuned.