It looks like to me that this merely allows 25 KHz. equipment to be purchased after January 1, 2011. It does not extend the date that VHF and UHF users must ***operate*** in Narrow mode past the previous January 1, 2013 deadline.
This makes it easier for users that will remain wide closer to the deadline to obtain new radios that still operate in the older wide mode. For example, the various FD's in my area are not narrowbanding the mutual aid and fireground channels until 2012 if an FD wanted to buy a new radio after the first of the year 2011 they would have had to operate in the narrow mode with the new radio while everyone else is wide. This allows them to buy radios with both wide and narrow modes up until the operational deadline so you don't have problems with new radios not being able to operate on a legal mode.