Apache already replaced IIRC almost all copyleft dependencies with BSD or Apache licensed code. AOO 4.0 is set to get a big GUI overhaul – I'm not aware of any similar plans in the LO camp.
My problem with LibreOffice / OpenOffice is the bad compatibility with MS Office, in particular Word. So for example if I create a document in Word with a TOC and open it in LibreOffice there is no TOC. In fact tables in general are problematic. Often I receive emails at my work email with Word attachments that have errors in LibreOffice.
When do you think LibreOffice will get a serious UI refresh ? I think it badly needs it. Not that it's not functional, but yes, when non techies compare it to Microsoft Office 2007/2010 they encounter at office, they find LO "ugly", or just "old looking".
I'm not sure just improve the openxml support justify the 4.0 version. Unless more java clean-up (ideally all) is done.