IMG tag

Thoughts on the IMG tag:

Because the draft says there still needs to be discussion on this: [Should 
we restrict the URI to pointing to an image? What's an image? Is PDF an 
image? (Safari supports PDFs in <img> elements.) How about SVG? (Opera 
supports those). WMFs? XPMs? HTML?] ....

I suggest allowing URI pointing to any file type that is not an html/xhtml 
document in it's own right (because they would have their own set of 
header and body tags).  The way a UA chooses to handle the different file 
formats would most likely be it's own decision (obviously normal images 
..jpg, .gif, .png, etc. would always be supported as normal) or set by the 
end user in the settings.  Could possibly just show an Icon for other file 
types if they elect not to have them traditionally embedded.  I think this 
would best conform to both historical use and newer uses such as the mobil 
web, where one might not want larger files (like WMFs, FLAs, etc) 
automatically fully embedded like images are.

Any thoughts?