I don't think that we've yet produced estimates for the work required to replace this. From what I recall the developers telling me in the past, the current uploader is part of the YUI library
tools that were used in the original development of AtoM. At this point, the entire library is deprecated, and no longer being maintained. Artefactual does monitor the plugin for relevant security issues, but at this point we need to replace the entire library, which I believe is responsible for certain other UI elements desperately in need of an update as well, such as the autcomplete lookup fields, for example. It doesn't really make sense for us to add a new component to replace one YUI element without replacing the whole library - we'd like to avoid that if at all possible. But we haven't yet done the analysis to determine the best replacement and figure out some estimates for the work involved in implementing it.
We have previously spent a bit of initial energy looking into potential crowd-funding platforms in the past, but in most cases, what we heard back from our users was that many institutions would not be able to secure funding towards something that did not have a definitive deliverable, like a development contract. Contributing money towards a feature that may or may not receive enough support to be implemented was much less likely for institutions who generally have to go through strict purchasing requirements, so we stopped pursuing it as an active funding option. However, we have worked with institutions to connect them to other institutions so that features can be collaboratively funded, but via the standard development contract route - in this case, what we need is one person/institution willing to be the designated point of contact (who will take on coordinating development requirements, testing, feedback, etc for all the participating partners), so that we don't have to try to coordinate with conflicting feedback and unclear chains of communication during a development contract.
I will speak to our developers and try to get some more information on what would they think be involved in replacing the YUI library elements - or at least all elements requiring Flash at present. We can possibly supply some rough ballparks / order of magnitude numbers and if there is serious interest, we can do further analysis to turn those into firm estimates.