Proposal for sending multiple files via XMLHttpRequest.send()

There has already been a discussion on extending XMLHttpRequest.send() to
take a File object. Could we also consider enhancing it further to support
sending multiple files, like a FileList from the drag and drop.

We could make XMLHttpRequest.send() take a FileList object and let the
browser add multipart boundary separators automatically.

Or, the other simpler way, thanks to Darin's suggestion, is to
extend XMLHttpRequest.send() to take an array of items. Each of item could
be either a string or a file reference strictly. The web application is
responsible to generate the multipart enevelop like the following:

    var payload = new Array;
    payload.push(header1);
    payload.push(file1);
    payload.push(footer1);
    ...
    xhr.send(payload);

How do you guys think about these approaches?

Thanks,

Jian