Currently when multiple files get selected only limited set of actions could be performed:
Would be fine same (or better even more extended) set of actions to be available like for single file "Open with...":

Currently possible actions, accessible with "Open with...", are strongly restricted to actions stricly following particular file type and only application registered for the particular file type could be used. In such a way actions/applications targeted more generally to any file, actions which should be available, get cut off! So some general files operations remain inaccessible (many types of attaching, for example). This could be easy fixed with let "relaxing" intent filters (Android developer must be able understand used terms). This is applicable for both - single selection and multiple selection, I think.
Accepting and delivering of both proposal would make Dropbox for Android usage more convenient in wider set of use cases!