I have a few that were sent in mid March and on WMR it says something like 'still processing a refund date will be provided when available".  

Another one that was sent in the beginning of March had that same message and then it changed to Refund Approved and then Refund Sent with the deposit date and amount (that was adjusted.....they claimed they didn't receive the $600 but must have according to the IRS).

All the ones that I know of that were being held up and were checked on WMR showed some type of message on it.