2. Nick Van Owen (Vince Vaughan)
I think we need at least one big character to make a return in order to link the original trilogy and Jurassic World together. And I think a recognisable star will help immensely. There is another (sounded a little Star Wars-ish there) but I'll come to her next. Of all the actors up for consideration, Vince Vaughan definitely has enough star power to keep selling films and he brought a lot of charm and humour to his role of Nick Van Owen in The Lost World. I kind of felt Nick got shafted at the end of the movie, though. He went through as much of an ordeal as Malcolm, Sarah and Kelly, and yet he's instantly forgotten the moment they get off the island, never to be seen again. According to IMDB, he's rumoured to make a return, though - without any other evidence to support this (I've looked) - there seems to be no confirmation on that front. As a documentarian, photo journalist and environmentalist, I'm sure he went on to use his experiences on Isla Sorna to further his career in big ways. After Hammond's speech, was he successful? I have a feeling, like Malcolm, that he might have a lot to say about the opening of a fully-realised theme park with dinosaurs.
How He Might Return...One of two ways. Firstly, he's a massively successful journalist (can't you see Vaughan playing up the celebrity lifestyle as an older, more confident Nick?). After his celebrated work on the return of dinosaurs to planet Earth, he's doing talk shows and interviews to give his own view on where John Hammond's legacy is headed. Another character from the past to warn the world as to the threat that awaits everyone? On the other hand, you could also go down the environmentalist activist route. Perhaps he's actively trying to sabotage the park before anyone is hurt? The cause of the inevitable incident or hero (like Erik) to lead people to safety? Or maybe it would be best to blend both of these characteristics.