Just want to add another vote here...I get a lot of image attachments and they make reading my mail via dial-up extremely frustrating. Even on my broadband connection, an email with a lot of images can take a LONG time to load. I'd much rather have the images suppressed.
So please, PRETTY PLEASE add a config setting/flag to disable the forced image view. It ought to be a very simple tweak, no? A few "if" statements in your HTML generation routines?