This is interesting; the reason cited is:If you click on it it says as of now but "subject to change" which leads me to believe they are simply basing that on rumors as well but I hope not.
S4GRU is claiming June 10th again based on internal documentation from product development.
S4GRU June 10th launch for EVO LTE
"LTE device connectivity in lab testing continues to be problematic due to under defined processes and complications around provisioning and SIM UICC profiles. Escalation of this issue is in progress."
Frankly, since LTE has barely been launched on the Sprint network, I'm of the mindset that they should just ship the device and then sort out LTE provisioning issues via subsequent software update... but then again I just want the LTEvo in my grubby little mitts.

Here's to irrationally hoping that this Mid-May release date is accurate.