I think btrfs could bring a bring a great safety net to such things.
Need to get 184 MB of archives.
~# apt-get dist-upgrade Get:1 http://ftp.uk.debian.org/debian/ wheezy/main dpkg amd64 1.16.2 [2,327 kB] . (etc..) . . After this operation, 516 kB disk space will be freed. Do you want to continue [Y/n]? Y Create pre-installation snapshot with btrfs [Y/n] Y
That would enable a full rollback in case of any packaging hiccups?