The buttons are about the same height. The difference that matters to me is the size and the location of a few buttons.
And as for when? I'm waiting for the 2013 to hit the refurb store to save some money. So probably 3 months or so based on previous models.
I got about three weeks before I receive mine so you won't be to far behind 😛. I wish apple would hurry up and distribute mavericks so I can get it for free, and while they are at it they should pull the plug on the Ipad 5.