Honestly I don't think there will be much of a change, if any. Adidas already owns Reebok so outside of the neck tag changing from the Reebok wordmark to the Adidas logo, I don't see any other changes they could make.
They are spending a ton for this contract, I think the article said twice as much as Reebok did last time, so I'm sure they will do what they can to increase sales, and what better way to do that than to force teams to change to new designs? Like I said, the fans will always buy their favorite team's new jersey.
Especially for hockey and the lettering. And, I agree about the pricing. Reebok paid through the nose for the license, and expected the fans to pay what they wanted. Not everyone is willing to spend that kind of money and they will settle for a knock-off. I have bought one jersey since the 05 lockout, and it was from the store in the Livingston mall when they were closing. Ron gave me a Rangers jersey for $40. It was a replica, but I'm not paying for the Edge, or Authentic, or whatever the hell they are called now.
P.S. If you are a collector, have some jerseys sitting in my closet I bought years ago I would sell for cheap. Bought most on EBay in the late 90s as I was starting a collection, but lost interest when I realized I really had no interest in displaying them. Never worn, some have tags, some tags have fallen off.
Picking out the fakes is easy for jersey collectors because we know what to look for, but I think for the everyday fan, it isn't as simple and becomes not worth the trouble to weed out the fakes. One of my old roommates is a big Rangers fan, and his girlfriend bought him a McDonagh jersey. He is aware of the prevalence of fake jerseys, and said he thought his was legit because he didn't see anything wrong with it, and wanted me to verify it for him. As soon he showed it to me I pointed out a handful of fake jersey characteristics that were present on his jersey. He even has a few officially-licensed replicas and still wasn't able to see the difference until I showed him.
I may be interested in your old jerseys, do you have a list of what they are?