Popping in to commiserate...huge hugs. It is sad when your excited kindergartener turns to no longer wanting to go to school! We are going through the same thing...ugh.

First 2 weeks- excitement at all the new experiences, bus, cafeteria, other kids, etc.
Then, boom, realization in my kid's mind that he KNOWS all of this stuff already. He came home so angry, and asked why he was doing 'baby' work with writing letters when he knows how to read. ugh.
He also said, "I don't feel PROUD of my work, Mama. It's all too easy."
Then yesterday he came home rip roaring mad, and said he had asked his teacher for more challenging work and she said, "No". His interpretation was that she said that he was still too young for more challenging work. ???? I have no idea what was said in reality, but his perception was what he described.
bleah.
I now have a meeting scheduled with his teacher for tomorrow. I know they are just getting to know the kids, but given how emotional my guy is, I feel I need to jump in and find a solution before he becomes truly disenchanted and angry.

So, I don't know if testing is the solution for us either, but I am going to open up dialog with the teacher and see what happens.
GOOD LUCK!