[CentOS] yum update gone wild? - new base?

I am being hit on a number of my systems with yum update reporting 270+ 
rpms to update, and MOST are coming from the base repo.  I checked a few 
out, and yes, they are of a higher release.

I don't recall ever seeing the base repo change; it is almost like it is 
picking up the the 6.4 base repo instead.

Anyone else seeing this.  I JUST did an install from my local repo copy 
of the 6.3 base and update using a netinstall kickstart, then yum tells 
me that there are 270+ updates...