ANet/NCSoft have little control over the retailer preorder process. You should ignore any information regarding release dates and prices until it comes from them.
Just to emphasize what was said in the posting above mine:
If you do not find it on our official website - ignore it.
Rest assured that we will be the first to let you all know about important things like release dates through our official channels.
I spotted this last week too. I see no logical reason to pre-order GW2 this early in advance. I mean, I'm assuming it will be much like GW1 where you can simply download the client and purchase the access key. If we do have to buy the cd, however, I'm sure they will be readily available come release day.