Since enTourage is at the point of recommending other e-readers and tablets, perhaps we should too.
One that caught my eye today is this review
of the Asus EEE Note, which about a month ago, was said to be imminently arriving in the US at a $200 price point. It's got an 8" backlight-free grayscale LCD with capacitive touchscreen and stylus input. The review says you can indeed annotate PDFs with it and read ePub format also. However, it runs a proprietary OS based on Linux, rather than Android, so there aren't any apps beyond those Asus provides.
Unfortunately in the comments the good e-reader person claims it will be a few months from now before it comes to the US. (it is already sold in Taiwan and the EU)