If i Pre-Order now?

I am a little confuesed, i was reading some posts and it sounds like there is a difference between the stores release version and the pre-order version...

Or can i get the "preorder" like from the guilwars.com(then threw Best buy for example) and play it a day earlier then just continue playing with that copy of the game or do i need to go buy a release version also?

This info is just from reading other posts and it got me worried! So if somone can clarify that would be great!

Thanks,
-Thumpy

PS: lol this is proly some newb question and yall are laughin at me

Please read all the stickies in the future. There is a sticky right there at the top of the Q&A section just for pre-orders.

Please read that thread, and post only after you check to see if your question hasn't already been answered by someone else.

Thank you ,
Aria