It would be nice if the --ignore list could be updated at runtime, while a specific package is downloading.

For example, I have some core updates to do and I want them done quickly, while at the same time I have to upgrade openoffice, firefox, java, kde and other big packages. Writing a pacman line to ignore these packages can get more time than it is needed to download and install everything, and forces the user to -Syu, Ctrl+C and "-Su --ignore x --ignore y...". This feature would allow people to press a shortcut that tells pacman to stop downloading $hugepackage, and adding it to the ignore list, so that it can be upgraded at a later time.

Of course, some care must be taken: if the skipped package is a dependency for another package on the upgrade list, and there's a version dependency, the other package should be skipped as well, and the user must be notified. In my ALPM ignorance I suppose it is equivalent to a dependency recalculation.