Despite ODF's recent acceptance as one industry standard, Microsoft has been fighting tooth and nail to get their version accepted in its place, Office Open XML. This time, they are coming out and and claiming that OpenDocument is just plain too slow
to be considered for use. To me, that seems a bit on the desperate side, and more of an attempt to simply discredit ODF rather than show the advantages Open XML might have. Others had similar things to say:
"There's simply no Open XML product on the market yet, to compare performance," Marcich said. "ODF is supported and implemented not just by OpenOffice, but by multiple applications including StarOffice, IBM Workplace, KOffice, Abiword/Gnumeric and Google Writely. All these applications have different performance behaviors."
Of course, there's no reason why both standards can't be accepted and implemented. However, it's unlikely that MS would be happy with dual standards.