You can run a simulation to see what would happen if you upgrade/install a package:
apt-get -s install
To see all possible upgrades, run a upgrade in verbose mode and (to be safe) with simulation, press n to cancel:
apt-get -V -s upgrade
The option policy can show the installed and the remote version (install candidate) of a package.
The console GUI of aptitude can display upgradeable packages with new versions. Open the menu ‘Upgradable Packages’. Pressing v on a package will show more detailed version information.
Or on the command-line:
Passing -V will show detailed information about versions, again to be safe with the simulation switch:
aptitude -V -s install
Another option, if you don’t know the full name of the package, is formatting aptitude’s search output:
%c = status (package installed or not)
%p = package’s name
%d = package’s description
%V = available package’s version
Another way using dpkg and grep: