I'm not talking about a centralized hiding, but a user specified hiding. e.g. next to each available package is a check box, and then at the bottom a "hide all selected packages".
Similarly, there would be a link to a "hidden packages" page, where one can selectively un-hide packages.
But sometimes there is just too much clutter on the available packages page, things that one knows one will never want to deal with always show up, making it harder to find what one wants or to see newly added packages.
If I can go once through the list, and either hide or install a package, then I end up with a list of "available" packages that is empty, unless something new shows up, which then is easy to spot.
Heck, another good addition would be batch install: same check box next to the packages, but then instead of "hide all selected packages" an "install all selecteded pakages" button...
Conversely, the same should be possible to de-install packages in bulk