It is Ribbon Interface and other interface tools more intergrated, new Power Wheel GUI, New 3D-Graphics, New Draw module which makes very easily to extract and annotate drawing, some new features like laser data process and many more.
All projects done and being developed with PDMS are fully compatible with E3D, all customised PML and catalogues will work on E3D environment.
I don't forget. :) Bocad is a separate application yet for the needs of structural engineers
Your company can ask Aveva for a webinar demonstrating E3D.
I saw somewhere article, that in future 2014 year they promised to glue bocad to e3d as separated module like Draft or Design or maybe even like Design application, like cable module..
Is good to mention that in E3D there is the LFM Laserscan Interface integrated in Design Module (that i know is part of the license).
Good improvement like already tought the new graphic and the new draft application....more Autocad Friendly.