I love my Tevas! I have ones that are similar to yours and my daughter got the ones your wife wore. I've been wearing mine to Disney for years! They are anti-bacterial and can be worn in the water yet dry really quickly. I'm a runner so I hate wearing tennis shoes except to run (makes your feet too hot!) and my doctor has recommended against crocs (they are really bad for people like me with 'bad' feet). I think you made a good choice but totally agree with other posters - wear them (a lot!) before you go to Disney! Take nice long evening walks and hit your local zoo and some other 'long' walk spots. It will help!
One other recommendation, change your shoes at Disney. While my doctor recommends changing your shoes everyday, I end up changing them 2 or 3x per day at Disney. It keeps your feet from hurting and it works! For me, Tevas in the AM, flip flops for the pool (only for the pool - horrible shoes to walk around parks - really bad for you for that), and dansko sandals for the PM.
I'm no doctor myself but I have really bad feet and have to take care of them. Being a runner also doesn't help my cause! So I've learned LOTS of shoe tricks!