I've been using iTunes Match since the day it was available, and have had no issues. Late last week I started getting the 4010 error some others have been reporting. The library information is gathered and upload to Apple without any apparent issue. It gets hung up at the point when the iTunes message "Waiting for Apple to deliver your iTunes Match results..." has been up for about 30 seconds. After that, the 4010 error appears.
I've tried all the usual tricks and resets, including signing out, creating a new iTunes library, etc., with no success. The error appears multiple computers under my account.
I'm guessing this is an Apple server issue, but I'm not hearing a lot about it, so I'm beginning to wonder if it's happening to a small number of us. Does anyone know if this is a widespread issue?
It's working for me, too. I turned iTunes Match back on this morning after I saw your post, and everything seems to be back to normal. I guess Apple was able to sort out whatever server issues they were having.