When viewing an attachment like a PDF in the current RC, I believe it uses your browser's built-in inline PDF viewer. For instance, if you viewed a PDF from RC in Safari on a Mac, it would render the PDF using Safari + Preview. Conversely, this would not work on Firefox from a Mac (using standard configuration); it would just offer to save the PDF to your drive instead.

However, this requires that there be a PDF viewer on your system AND that your browser be configured to use it to display inline PDFs inside the browser. These aren't always available or easy to configure for some people.

It'd be nice to have a built-in attachment viewer in RC to handle these types of documents in any browser/OS configuration. Something like: http://view.samurajdata.se/ which can render PDF, PS, and Word Documents in a simple preview inside the browser.

This would be similar to how Gmail is setup: a "preview" link and a "download" link.

Any ideas or further suggestions on this?

Too much third party software as pre-requirements, IMO. So it will cause portability problems. Just my 2cents.