I have a different perspective for you to consider. Your main issue is that it hides logic and there is data and applications scattered through the organization.
Unfortunately I don't know of a RAD (rapid application development) tool that is as easy as Access to create functional forms.
However I would recommend that you focus more on the possibility of centeralizing your data and logic and still allow Access as a front end. I support a database product called Advantage Database Server which supports RI (refferential integrity) rules, stored procedures, triggers, etc. that can all be managed on a centeral server thus bringing all of the logic to you. These Access front-ends could then link to the data backend using ODBC or OLEDB. If you switched to a solution like this then later down the road you would have flexibility to write other applications such as .NET, PHP, JDBC, etc. that tie into the same data while phasing Access front-ends out.
A good start would be to stop new Access development unless they're using this sort of data backend.
