But then again I haven't tested OpenGL on any integrated-chipset-graphics
Continuing to be off-topic:
At work I have a desktop with intel integrated chipset which performs I suspect well enough for 2d games (my 3d game still is playable on it). Especially when you want to do fancy stuff like rotation and blending you will have better performance using ogl on those chipsets.
And on wintel java2d might perform not too bad for simple stuff, it's still buggy and not reliable on that platform.
And remember that the playspeed will be a problem sooner or later when you want to make a game without some native help.
I said it before and I say it again:
Java2d for games: never again for me.