Looks like we've got some heavy hitters closing this week with both Equestrian Training and Mario Strikers Battle League Closing. 

What Does it mean Pre-orders are closing?

You will still be able to pre-order these titles however your order will likely miss street-date. While street date is never fully guaranteed, 99% of pre-orders placed during the open period do deliver on time. 

You can always keep up to date with what is closing here.