According to the "new upcoming" phone list for Sprint, the HTC EVO ONE(LTE) is listed for a June 6th release date...and I believe the old EVO4G got its software update around the time the EVO3D was released...so just basing it off that, the ICS update should come around that time, if not before that (hoping)...but like said before...who knows
The old EVO received its update on June 3rd of 2011. The EVO 3D was released on the 24th of the same month. So there was a few weeks in between.