HTC shared this statement regarding the HTC EVO 4G LTE:
“The US availability of HTC One X and HTC EVO 4G LTE has been delayed due to a standard U.S. Customs review of shipments that is required after an ITC exclusion order. We believe we are in compliance with the ruling and HTC is working closely with Customs to secure approval. HTC One X and HTC EVO 4G LTE have both received enthusiastic support and we appreciate customers patience as we work to get these products into their hands as soon as possible.”
Here's Information from Sprint:
HTC EVO 4G LTE availability
The U.S. availability of the HTC EVO 4G LTE has been delayed. HTC is working to resolve this issue and appreciates your patience as they work to get products into Sprint channels. We can’t provide specific timing for product availability at this time and we appreciate your patience as HTC works to get products on store shelves as soon as possible.
Delivery of products for pre-order are on hold and Sprint will provide a ship date as soon as possible. Sprint will maintain the promise for the preorder customers that they will be among the first to receive their HTC EVO 4G LTE units.
While we'd rather you didn't cancel your pre-order, there are instructions provided in the backorder email on how to do so. I've pasted them here for your reference:
If you would like to select an alternate product or cancel your backordered item, please call 866-789-8292 between 8:00 a.m. EST to 11:00 p.m. EST Monday to Friday or 9:00 a.m. EST to 9:00 p.m. EST on Saturdays and Sundays.Please note that cancellation requests may not always process successfully due to the speed of warehouse processing.If you cancelled your backordered item but still received a shipment, please refuse the shipment or call us to process a return within 14 days of receipt.