Bethesda/Zenimax now has the pre-order info on their website
here.
The only 'pay to win' related thing in the Imperial edition seems to the Rings of Mara that allows for an unspecified experience boost if you play with a friend.
The five day head start and ability to play as any race in any alliance seem to be pre-order bonuses for any edition.
While I'm not a huge fan of CE's and vanity stuff, in this case I don't mind giving them an extra 20 bucks for the Imperial edition bonuses because I've gotten way more than my monies worth out of Skyrim.
edit: spelling
This comment was edited on Jan 29, 2014, 12:17.