It says "This takes loooooooooong" upon install.

Well, why don't you print progress messages?

Because according to top(1) your program is doing nothing at all.

We are just sitting there waiting for 100 packages upgrade to complete,
and bbdb is just stalled asking us to wait a long time but in fact
permanently out to lunch stalled.

$ pstree -Ala
init
  |-exim4 -bd -q30m
  |-gpg --with-colons --list-config
  |-gpg --with-colons --list-config
  |-gpg --with-colons --list-config
  |-gpg --with-colons --list-config
  |-init
  |   `-bash
  |       |-aptitude install bbdb
  |       |   |-dpkg --status-fd 25 --configure bbdb
  |       |   |   `-bbdb.postinst /var/lib/dpkg/info/bbdb.postinst configure
  |       |   |       `-emacs-package-i -w /usr/lib/emacsen-common/emacs-package-install bbdb
  |       |   |           |-bbdb /usr/lib/emacsen-common/packages/install/bbdb emacs-snapshot emacs-snapshot
  |       |   |           |   `-bbdb /usr/lib/emacsen-common/packages/install/bbdb emacs-snapshot emacs-snapshot
  |       |   |           |       `-make rmail mhe gnus bbdb EMACS_PROG=emacs-snapshot VMDIR=/usr/share/emacs-snapshot/site-lisp/vm GNUSDIR=/usr/share/emacs-snapshot/site-lisp/../lisp/gnus MHEDIR=/usr/share/emacs-snapshot/site-lisp/../lisp/mail
  |       |   |           |           `-sh -c cd lisp; make rmail
  |       |   |           |               `-make rmail
  |       |   |           |                   `-emacs-snapshot -batch -q -eval (setq load-path (append (list\012(expand-file-name ".") \012) load-path)) -l ./bbdb.elc -eval (and (not (string= "/usr/share/emacs-snapshot/site-lisp/vm" "")) \011    (setq load-path (cons "/usr/share/emacs-snapshot/site-lisp/vm" load-path)) \011    (load "vm" t t) \011    (load "vm-vars" t t)) -f batch-byte-compile bbdb-hooks.el
  |       |   |           |                       `-gpg --with-colons --list-config
  |       |   |           `-(emacs-package-i)
  |       |   `-2*[{aptitude}]
  |       |-emacs /var/cache/apt/archives/
  |       |   `-bash --noediting -i
  |       `-emacs --debug-init

I sent a bug report about the whole emacs-snapshot 1:20100602-1 being
uninstallable but the bug number hasn't got back to me yet.