A change of this magnitude isn't accomplished in a short time.
I don't want to scare anybody off but it takes years.
JP, from my experiences it does not need to take years to make this transition. It requires the proper training of ALL individuals at the same time. In this manner everyone sees how the application should be applied to the engineering tasks that they face day to day. Piecemeal, top down, or bottom up training isn't going to cut. This trickle down approach will not create the momentum required to overcome organizational inertia.
When the users get a really good example of how, when and where the program makes their life easier and the design process faster, most a quick to adopt it. When the training they receive is too abstract, i.e. not their project data, it becomes an obstacle moving from the abstract to practical application. For the best examples of this one need only look around here (The Swamp) at how well my students have progressed with C3D, and their willingness to continue to struggle with the applications inherent flaws, or omissions; exactly because they have seen how much it can do for them in spite of these challenges.
Conversely; I also have clients that have failed to successfully adopt C3D for a variety of reasons. Most of them have been instances where they have asked me to deviate from my normal plan of attack. Two examples come to mind; one wherein the 'lead' designed failed to accept that his design methods would need to adjust to the toolkit and workflow that C3D presents. The other was caused by the principal engineer deciding that various users would attend only bits and pieces of the classes resulting in most not seeing the package in its entirety and all not getting the complete picture of the processes or power of C3D.
This entire process could and should go a lot smoother, if only Autodesk would listen to the users and fix the problems in the application; not in the next release, or the next, but right now and at NO CHARGE to the customers who have already paid (and suffered) enough with the idiosyncrasies of Civil 3D from the beginning. However, this is probably very unlikely, when they and their puppets over at augi, censor (delete) any post there or the newsgroups that no matter how true they find objectionable. They fail to understand that the truth is immutable. Thank goodness that The Swamp isn't adversely affected by any corporate affiliation with Autodesk, or SolidVapour.