One of the things I use the most in Gmail is the "View as HTML" feature for previewing documents, presentations, and spreadsheets that are attached to an email. This lets you scope out what a document is about without having to download it to your computer.
It does, however, have some limitations. One of the things this feature never did in the past was display images or graphs. That’s no longer true when you’re viewing a DOC file in an HTML format as seen in the screenshot above. I took one of our recent posts that we did this morning, copied the content into Microsoft Word, and saved it in a DOC format. Then I emailed it to myself and used the HTML preview to see how well it rendered the image.
Judging by the side-by-side comparison above I would say that the two results are pretty identical, and the View as HTML feature in Gmail just got a lot more useful! The bad news is that this feature only works for DOC files for the time being, and doesn’t seem to apply to spreadsheets or presentations. To get a preview of what those files you would need to use the specialized Google offerings, such as this one for presentations.
Now I would like to see Google do is add some support for the Office 2007 file formats. I’ve been receiving quite a few attachments with the DOCX filetype, and I have to download them in order to view the contents.
Source: Google Operating System