HTML Import for Web Designers

I've tried searching for messages regarding duplicate custom elements, but
I haven't found anything.  Has this been addressed?  It seems that if a web
designer wants to use multiple libraries that may register the same tag
names, this would prevent the web designer from using said components until
they rewrote the underlying component to rename it.

It would be nice if the web designer could use components without fear of
having to rewrite someone else's components.

<link rel="import" href="toolset1/toolbar.html" namespace="tool1" />
<link rel="import" href="toolset2/toolbar.html" namespace="tool2" />

where if the component code calls

var ele = document.registerElement("x-toolbar");

it would instead create <tool1-x-toolbar> and <tool2-x-toolbar>
respectively.  If the designer wants to know what tag he actually received,

ele.tagName ( should report the actual registered name )

Also any <link>s in the component would get that namespace as well.