Here's a portion of the calculated upgrade from precise to trusty with -proposed enabled.

Ign http://192.168.10.7 trusty/main Translation-en                
Ign http://192.168.10.7 trusty/multiverse Translation-en
Ign http://192.168.10.7 trusty/restricted Translation-en
Ign http://192.168.10.7 trusty/universe Translation-en
Fetched 26.2 MB in 3s (7102 kB/s) 
Reading package lists... Done
(precise-amd64)root@impulse:/tmp/bug-839378# apt-get dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following NEW packages will be installed:
  attr cpp-4.8 g++-4.8 gcc-4.8 gcc-4.8-base gcc-4.9-base iproute2 isc-dhcp-client isc-dhcp-common kmod libaio1 libapt-inst1.5
  libarchive-extract-perl libasan0 libatm1 libatomic1 libaudit-common libaudit1 libbsd0 libcgmanager0 libcloog-isl4 libdb5.3 libdebconfclient0
  libfakeroot libfile-fcntllock-perl libgcc-4.8-dev libhdb9-heimdal libisl10 libitm1 libjson-c2 libjson0 libkdc2-heimdal libkmod2 libldb1
  liblog-message-simple-perl libmodule-pluggable-perl libmpc3 libnss-winbind libntdb1 libpod-latex-perl libprocps3 libpython-stdlib
  libpython2.7-minimal libpython2.7-stdlib libsasl2-modules-db libsemanage-common libsemanage1 libsepol1 libstdc++-4.8-dev libtasn1-6
  libterm-ui-perl libtevent0 libtext-soundex-perl libtsan0 libudev1 libustr-1.0-1 libxtables10 python python-crypto python-dnspython python-ldb
  python-ntdb python-samba python-talloc python-tdb samba-dsdb-modules samba-libs samba-vfs-modules
The following packages will be upgraded:
  adduser advancecomp apt apt-utils base-files base-passwd bash binutils bsdutils build-essential busybox-initramfs bzip2 coreutils cpio cpp
  cpp-4.6 cron dash debconf debianutils diffutils dpkg dpkg-dev e2fslibs e2fsprogs fakeroot findutils g++ g++-4.6 gcc gcc-4.6 gcc-4.6-base gnupg
  gpgv grep gzip hostname ifupdown initramfs-tools initramfs-tools-bin initscripts insserv iproute klibc-utils krb5-locales libacl1
  libalgorithm-diff-perl libalgorithm-diff-xs-perl libapt-pkg4.12 libasn1-8-heimdal libattr1 libavahi-client3 libavahi-common-data
  libavahi-common3 libblkid1 libbz2-1.0 libc-bin libc-dev-bin libc6 libc6-dev libcap2 libclass-isa-perl libcomerr2 libcups2 libdb5.1 libdbus-1-3
  libdpkg-perl libdrm-intel1 libdrm-radeon1 libdrm2 libelf1 libexpat1 libffi6 libgcc1 libgcrypt11 libgdbm3 libglib2.0-0 libgmp10 libgnutls26
  libgomp1 libgpg-error0 libgpm2 libgssapi-krb5-2 libgssapi3-heimdal libhcrypto4-heimdal libheimbase1-heimdal libheimntlm0-heimdal
  libhx509-5-heimdal libk5crypto3 libkeyutils1 libklibc libkrb5-26-heimdal libkrb5-3 libkrb5support0 libldap-2.4-2 liblockfile-bin liblockfile1
  liblzma5 libmount1 libmpfr4 libncurses5 libncursesw5 libnih-dbus1 libnih1 libp11-kit0 libpam-modules libpam-modules-bin libpam-runtime
  libpam-winbind libpam0g libpciaccess0 libpcre3 libplymouth2 libpng12-0 libpopt0 libpython2.7 libquadmath0 libreadline6 libroken18-heimdal
  libsasl2-2 libsasl2-modules libselinux1 libslang2 libsqlite3-0 libss2 libssl1.0.0 libstdc++6 libstdc++6-4.6-dev libtalloc2 libtdb1
  libtimedate-perl libtinfo5 libusb-0.1-4 libuuid1 libwbclient0 libwind0-heimdal linux-libc-dev locales lockfile-progs login logrotate lsb-base
  make makedev manpages manpages-dev mawk mime-support module-init-tools mount mountall multiarch-support ncurses-base ncurses-bin netbase optipng
  passwd patch perl perl-base perl-modules pkg-create-dbgsym pkgbinarymangler plymouth procps python-minimal python2.7 python2.7-minimal
  readline-common samba samba-common samba-common-bin sed sensible-utils sudo sysv-rc sysvinit-utils tar tdb-tools tzdata ubuntu-keyring ucf udev
  update-inetd upstart util-linux vim vim-common vim-runtime winbind xz-utils zlib1g
192 upgraded, 68 newly installed, 0 to remove and 0 not upgraded.
Need to get 105 MB of archives.
After this operation, 89.2 MB of additional disk space will be used.