Google Books provides a way of reading (DRMed) ePub on your Kindle using its web browser. On my K3, it works rather well. It's as if I just got a free upgrade to read ePub...
I'm trying it on my K2 but it is very slow (I have only 1x) and does not seem to work (I don't get a 'Read' button to launch the web ebook viewer). Maybe Google can fix this, or maybe K2/DX is out of luck...