i'd like to suggest adding an autocompletion feature to the text based form components.
Especially for the usecase of tagging this would prevent misspelled tags and thus unnecessary redundancy.
By now this can only be achieved via a "hard coded" combobox or based on data sources, which needs more time to search for the right value.
For the look and feel i personally like the jQueryUI autocomplete, as it is very simple: http://jqueryui.com/autocomplete/. And from a technical point of view i would like an API that allows me connecting all kinds of data sources with a custom connector (FS DS, external DS, catalogue in project settings, etc.) and the option of multiple values (as this community offers ;-)).