Though squid are indeed very much more intelligent than would be expected for an invertebrate, they don’t really rank compared to mammals.
Secondly, I strongly suspect the route to increased intelligence, at least in the beginning, will be the splicing of human genes into animal DNA. For this to work the animals brain will need to be of similar structure to a human brain. This means we will only be able to enhance mammals with any reasonable chance of success. Though Apes are our nearest relatives, it makes little practical sense to enhance them, as they are so similar to us in physical capability, and will be the least likely to be seen as “still animal” if they reach the intelligence for being given simple jobs via simple communication.
Dogs are promising, as they have a very good tendency to work with humans and have superb stamina and senses. Dolphins would be another good choice, since they have significant underwater freedom of movement, and are already highly intelligent.
What would be cool, brain transplants…think about it. Cross species transplants, insert chimp or dolphin brain into a human.
vice versa = scary Imagine you die in a tragic accident and wake as dolphin with memory intact.
Seriously, I think it might be possible to surgically alter/replace the vocal chords of a chimp. To what end? Dunno perhaps an interpretive/translator. Maybe train apes for hazardous duties.
AI possibilities…hmmm Near infinite intelligence w/ reasoning & problem solving skills, cool. Well, maybe not remember “War Games” , “2001” , “Planet of the Apes”, Justhink, etc. 
I’m waiting…But, I can still give my PC a challenge and often beat it at chess. I think it’ll be awhile yet. Although it does seem to have a mind of its own sometimes. 
Yes. I predict that we should have something at least approximating AI in about 20 years.
Of course, scientists have been saying “20 years” since 1950, so you are welcome to draw your own conclusions.
The book Eva, by Peter Dickinson, explores that second scenario. But with a chimp instead of a dolphin. And I don’t think a human brain was implanted, but the human memories were transferred.
Funny but when I originally read the OP my first thought was “when are they going to engineer an intelligent Human race”. In retrospect I’m afraid I was more accurate than I realized, not funny.
BTW east e for some reason the book you mentioned sounds strangely familiar. I never read it though I’m sure.