CentOS 5.1 -> 5.2. Yum update problem

Today I wanted to update my CentOS 5.1 Server to current release - CentOS 5.2. After #yum update I got an error:
Error: Missing Dependency: libegroupwise-1.2.so.12 is needed by package evolution
and no update possible. After couple moments my amazing brain foud resolution (I really have no idea how it - brain - knows those things ;) ).

I downloaded .iso of CentOS 5.2 and mounted it in loop mode:

#mount -o loop /path-to-iso/CentOS-5.2-i386-bin-DVD.iso /mnt/cd
#cd /mnt/cd/CentOS/
#for i in *.rpm
> do
> yum localupdate $i
> done

.... and here I made mistake. Much more smarter would be: > yum -y localupdate $i . I had to spent two hours typing y, Enter :/

Anyway, it's one of resolutions but I have to find better because in company I work there is about 20 servers to be updated and this way is not very efficient.