I would like to see someone give Senna a chance as well. He's shown a lot of promise at Lotus even though he's had some fairly poor results as well. I think he could be very good, given the chance. That said, so could a lot of young drivers.
As much as I like Barrichello, I think he should have bowed out gracefully, but I understand why he wouldn't want to. It's probably the best job in the world! Trulli on the other hand, I don't see his value in F1 any more. He's never appeared to have made much impact in Caterham and seems to have had issues with power steering forever. I'm sure his experience was valuable at some point, but now Caterham are looking to move upwards (and looking more and more like they will be firmly midfield next season) it's time they got someone fresher and faster in. It's not like Heikki has little experience, he has plenty to keep them going. They should give a new young driver a chance!