I believe it will be great if Zotero were to pop up when I rolled over the taskbar icon, and then if it went away when I rolled out of the zotero sub window.

E.g. If I'm reading a list of articles and then feel like filing one away in one of my collections, I can hover to bring up Zotero, select the collection, go back to the full firefox window to see my full list and select to download something, then open a pdf, hover over zotero, take a snapshot and attach it to the article, then hover out and go back to reading the pdf full screen...

At present a similar effect could be achieved with the shortcut key (requires switch to keyboard) or by clicking on the zotero icon (requires accurate clicking effort). However, a more fluid response would greatly enhance the user experience.

It could be disabled through the configuration dialog... most pop up facilities e.g. windows start bar, have options to disable pop up.