I believe it is the high time to introduce a search field in "Apps\Get More Apps..." menu. There are so many apps in the list that a search query would be extremely useful.
I think it would also be useful to merge all the currently available options in "Apps\Get More Apps..." menu (by category, title, new releases, recently updated) into just one - "Get More Apps" and move/port the selections/filter you can sort by into the window of all the apps instead.