I had this issue for the first day after updating to iOS6. One important thing I found is that restarting the phone did not reset the apps. Also, I went to a Softbank (Japan) store on Friday and gigled to myself when I saw an iPad with infinitely updating apps on the homescreen. You are not the only one.
I got incredibly frustrated with it and uninstalled all of the "waiting"/"installing" apps that just sat there unusable. I then waited until Friday. Now, I have no problem updating or downloading the apps that I previously removed. It was a big hassle to take a not of all the apps I had to reinstall, but I did it. Another problem is if you fear loosing data.
I am not sure what the best solution is, but that is what I did. Hope things get better for you.