I saw a TED talk about a team of researchers who are trying to decode the language of dolphins so that we can communicate with them. They have started to do this with wearable computers and games involving toys, and have included new sounds for the names of those toys and also for themselves. So far, the dolphins seem like they might be communicating to some degree. This all sounds very exciting from one angle. Dolphins might have a language! Maybe we can communicate with them! Share with us the wisdom of the sea, oh gentle beasts!
Rewind about thirty or forty years, though, and exactly the same thing was done with chimps. A lot of research time, a lot of money and a lot of hope went into those projects, teaching chimps and apes sign language, only to find out that they couldn't learn anything past a two-year-old's disjointed use of vocabulary and they had very little to say to us besides "want that".
As much fun as the researchers might have, and as much interesting science might come out of it, I think we'll find that dolphins, like chimps, might have some intelligence, but it is a far cry from the human levels of sophistication in language.
Mokalus of Borg
PS - They probably can't even grasp the concepts behind "So long, and thanks for all the fish".
PPS - Or maybe they could, but it would be much more like thinking in pictures.