removal of frame / frameset - how will user resizeable panes be supported?

Hello,

With reference to: http://www.w3.org/TR/2008/WD-html5-diff-20080122/

 > The following elements are not in HTML 5 because their usage affected 
 > usability and accessibility for the end user in a negative way:
 >   * frame
 >   * frameset
 >   * noframes


Please provide an indication / recomendation on how pages with user 
resizeable frames (panes) would be supported in HTML5.

Imagine a simple page with two frames; one pane contains an index or 
table-of-contents, the other is updated with detailed content by 
clicking on links in the index.

A user is able to resize the detailed pane to their monitor / 
preferences to balance the visual size of the index vs the size of the 
associated detailed content.

Recommendations on how this would be handled in HTML5 would be much 
appreciated.

Regards

Jeff