Merge into CDN module?

With great interest, I read #1182670: Integrate with the CDN module. Especially comments #25 and #38.

Regarding #30:

This is a bit tricky, i am troubled by cdn's approach of only those who knows php will be able to pull this off.

The thing is that, for most sites, it is sufficient to simply offload the images to one domain. You need a lot of images per page, otherwise it's just not worth it. Nevertheless, I'd like to see this improved.

Plus, I'd like to make sure that CSS background images are automatically served from a CDN with just the CDN module. Then I could say: "just install the advagg module and it'll work automatically" (I'd prefer it to work even without the advagg module, but that's just impossible). It would greatly simplify setting this up for the end user.

What do you think about this: instead of allowing one domain per line, allow multiple domains per line, separated by spaces. Let me give an example. Currently, you can only enter mappings like such:

http://cdn-a.com|.css .jpg .jpeg .png

If I'd also support this:

http://cdn-a.com http://cdn-b.com http://cdn-c.com|.css .jpg .jpeg .png, then we could do the balancing automatically.

What do you say? :) The syntax surely seems simple enough.