if u ever play P:R before, u should notice that under ur player info, there are other factions like firekkan, nephilim and etc. in WCU rather than the confed, pirates, kilrathi, retro, hunters and merchant.
besides, there are a large numbers of ship added in WCU and some attributes changes of the previous ship. one thing can be noticeable quiet easily is the jump bubble...
and the sectors of WCU cover up to sol, vega, enigma and etc, rather than just the gemini sector, u can buy these maps from the software upgrade panel... there r some system u hav to explore yourself coz its not available to be purchase...
there are more diffrences, those i mentioned were just some examples...
Have a great time exploring!!