I've thought about the rumours of the original trio signing on for ST. According to my sources, EPVII will be close after Battle of Endor in timeline, which lead me to believe it's highly unlikely that Ford for instance will be portraying Han Solo. My guess is that the original trio will show up in cameo roles, like Ford portraiting the eldely Corellian senator, Hamill being the junk dealer at Tatooine etc . But what if they introduced time travelling in the SW universe? (Not sure if the EU already introduced it.) Then it would be possible to do something like they did in the Star Trek movie, when Leonard Nimoy showed up as an older Spock. This way they could create the young Organa/Skywalker/Solo in CGI and then let these characters meet their older versions, portraited by Fisher/Hamill/Ford. Sounds cool if you ask me.