[x] trim plugin desc to short summary, provide 'more info' trigger, and on click display a fancybox window with markdown parsed (cf showdown.js) desc.
[x] CF. WP (screenshot), inline (De)Activate / (Un)Install buttons would free space for an Updated date/ Popularity column, and perhaps even replace the standard 'Installed plugins' tab (because Plugin Installer would incorporate all its features plus extras)
[ ] Not a fan of the 'multi-(un)install' feature. If 1 out of 10 plugins fail to install, what feedback is given?
Also haven't seen this feature in any CMS until now (activation yes, but not install)
Ideas: