Mixed news, I’m afraid. I’ve tried it out with one of the magazines – http://download.microsoft.com/download/3/a/7/3a7fa450-1f33-41f7-9e6d-3aa95b5a6aea/MSDNMagazine2009_07en-us.chm
Bad news: It didn’t detect the .CHM file, so there was no way of reading it.
Good news: I unzipped the file and copied the directory to the eReader – I was able to open up the individual .HTM files.
Bad news: It didn’t display the inline images and there’s no clickable navigation.
So, a bit mixed for you. You can certainly read the text – and search it – but it won’t look wonderful. You can always convert the CHM into a PDF or ePub – take a look at http://wiki.mobileread.com/wiki/E-book_conversion
I’ll edit the information on the MobileRead Wiki.