OpenDocument as an archival format

In the eWeek.com news article "Sun Pushes for Greater Adoption of 
OpenDocument Format":

  http://www.eweek.com/article2/0,1759,1901966,00.asp

The following is written:

  "The ODF file format is also designed to be compatible with Microsoft 
   Office, as the technical committee working on this knew it was going to  
   be used to import and export a lot of Microsoft Office documents, 
   Phipps said, adding that he did not believe the format would end up as 
   an archival format."

What is the reason that OpenDocument would not be used as an archival 
format. Isn't this one of the biggest pros for OpenDocument that I will 
always be readable - even hundreds of years from now.

The most enjoyable greetings
-- 
Claus Agerskov        OpenDocument er en 嶙en standard for kontordokumenter,
OpenDocument.dk       som  anbefales af blandt  andet  EU.   OpenDocument er
    standardformatet i de nyeste udgaver af OpenOffice.org,
+45 27 59 69 96       KOffice og StarOffice.