Here's how I think it'll pan out.
Kinect is released. Because there are no existing Hardcore Kinect games, Kinect won't appeal to existing 360 owners because most 360 owners are hardcore. Existing 360 owners won't purchase Kinect, at least not enough to make an impact. Kinect may appeal to casual gamers. However, most casual gamers don't own 360s. So any interested consumers will have to buy a new 360 and Kinect and $60 games (if those are the actual prices). That's too much for games that look similar to the wii. Also Microsoft is known too heavily promote games. I expect to see ads for hardcore 360 games one minute (Halo, COD, MGS:R, etc), and then ads for Kinect games (Kinectimals, Kinect adventures, etc) the next. This may send mixed messages to interested buyers, both casual and hardcore. Casuals will see 360 as too hardcore, while core games will see kinect as too casual. So basically, existing 360 gamers won't buy kinect because it's casual. Non-existing 360 owners won't buy it because the 360 is is seen as a hardcore console, and it'll be too risky when they already have a wii. It will only be worse it there is noticable lag (as many analyst say). I predict a failure.
As for the move, I predict something different. Based on e3, Sony already has hardcore games being developed for move (Kilzone 3, SOCOM 4, Sorcery, Heavy Rain, etc) and I expect this to continue. So, unlike kinect, this will appeal to existing ps3 owners. Existing ps3 owners will buy it and it'll work great (based on what analyst say). At only 100 bucks, ps3 owners will buy the move bundle and will love it because of the games and precision. They may also buy the navigation thingy and another wand. Move will develop a name for itself and maybe non-existing ps3 will buy a ps3 just for move. So basically, Move will sell amongst ps3 owners and may or may not move consoles.
I believe move will outsell kinect. As for Move being expensive for multiple players, have you ever heard of taking turns. Most of the games I saw were single-player made games. As for Kinect outselling move on Amazon. That's beacuse of all the actors, celebrities, and mainstream TV shows showcasing pre-rendering kinect demos. All the uninformed gamers see it and think "OMG It's the future". Then find out the price of Kinect along with a 360 and the expensive games. Most will cancel their orders. Some will still accept kinect. Then they finally get Kinect and realize what a mistake they made.
The only way kinect can sell is by 1.) attract 360 owners 2.) get rid of the lag problems, and 3.) make games different form wii. Oh and it has to work sitting down.