I wasn’t aware that Microsoft had any real entry into the eBook reader world but thanks to MobileRead Networks, I do now! They have in fact, got a whole web site devoted to it here.
From that site you can download “Microsoft Reader” a “free, downloadable software application that allows you to read eBooks on Windows-based devices you may already own.” which sounds pretty good to me 
There are 3 versions of the software for Desktops/Laptops, Tablets & UMPC’s and Pocket PC’s.
eBooks seem like a great idea but I can’t be bothered to get another device a la Kindle so being able to read eBooks on my HTC Diamond seems like a good idea. Yeah, the screen isn’t particularly big but I don’t mind-the convenience wins for me.
*Update* I’ve been doing a bit of Googling and it seems that MS Reader doesn’t yet work with WinMo 6.1, which is a bummer. It will install but won’t activate, which is always the key part with Microsoft The forum post here shows that MS are aware of it (as do other Google finds) but there still doesn’t seem to be a fix. This is a shame as it’s going to put a lot of people off upgrading to 6.1 and then people like me who are already on 6.1 are stuck 
When and if I hear something further, I’ll update this post ASAP!
