upgrade dist from squeeze to wheezy

[prad <prad@towardsfreedom.com>]

we have been on squeeze for a couple of years and run a server using
openvz. we also have some backports and some software in /usr/local we
compiled (so we could use more updated versions).

we want to do a dist upgrade to wheezy.

is the correct process:

1. uninstall backports and /usr/local software
2. run aptitude dist-upgrade on main system
3. run aptitude dist-upgrade on openvz server

are there any issues we should be aware/cautious about or do things go
pretty smoothly?

-- 
in friendship,
prad