Given the number of generations (your 'great' list) and what I saw between starting in the computer/software industry in Jan 1984 and when I retired in Nov 2009, the structure, form, and storage of information will likely be very different. Just the capabilities of genealogy software has changed dramatically during those 26 years.
The future capabilities of technology is always a guess. Might I suggest you look at which organizations (for example, genealogical or historical societies) nears where your ancestors resided. Then speak with representatives of those organizations about format. Please remember to leave specific instructions in your will to provide those organizations with the copies of your information in the format those organizations suggest.