I will third the suggestion that you amend your considerations to look between the Kindle and the Kobo.
And just for the record -- it is REALLY convenient to checkout a book and have it sent wirelessly without ever leaving the browser. Adobe Digital Editions is REALLY awkward to use...
If you choose a Kindle you can still hack it, see this post before doing anything:
http://mobileread.com/forums/showpost.php?p=2978681
Chances are PW2s will still be coming with older firmware, from when it was first packaged -- but they will definitely have an OTA update waiting.