When I ordered my X51 a few years back it came 2 weeks earlier than the estimated time of delivery. However I live near Tennessee which houses the major FedEx hub so getting it sooner was expected. Then when my X51 pooped out the first time I sent it off and they sent me a completely new one with an updated graphics card at no charge whatsoever and only took 4 business days. It all depends on where you order from (Amazon, wal mart, etc.) and where you live in the states. Oh and like years ago when I used to slither around these forums nobody is going to want to reply to your questions much because everyone just wants a hand out via the ARP system.
edit: You’ll get a notification when your order has actually shipped. Login to your Dell account, Order Support, enter order # (not a shipping number, this is your order #) and it will tell you your updated status. You’ll see your estimated ship date and arrival date at the bottom of the page. Once your PC has shipped Dell will create you a shipping # and then you can track your package on the carriers website or from Dell directly.