Converting XML Datetime to SQL Datetime

Declare @Xml Xml
Set @Xml = '<Root><DateFrom>2008-10-31T00:00:00</DateFrom></Root>'

Declare @DateFrom DateTime
Set @DateFrom = ?????

Declare @Xml Xml
Set @Xml = '<Root><DateFrom>8/10/2008</DateFrom></Root>'

Declare @DateFrom DateTime
Select @DateFrom= t.b.value('DateFrom[1]', 'datetime')
from @xml.nodes('//Root') t(b)