First, what I liked:
The book had an interesting premise: it's about both first contact and aging (or the lack thereof - almost like time travel). Some of the concepts the explored about extra-terrestials were quite novel, blowing away some of the widely-held beliefs that were put in place by the likes of Carl Sagan.
However... there was a lot that I didn't care for in the book.
The first was the author's idea of what things might be like 30-40 years from now. I'm not talking about "futuristic" things, like flying cars or robots; I'm talking about ideas from our present that would continue through the decades: from debatable items (like global warming) to outright fads (like Atkins, which has already been replaced by the South Beach Diet, which in turn is likely to be replaced as the diet-du-jour), the things the author believes to be enduring trends, I found to be rather unbelieveable.
The second - and I might be due to the author being Canadian, and therefore more socially liberal than Americans coupled with my own religious conservatism - is that there were many liberal ideas that were presented, not just as one belief or philosophy among many, but as superior to them all. One of the major plot points seems to revolve around the controverserial topic of abortion. There are entire chapters devoted to the topic of abortion - this is surprising (and the conclusions, quite frankly, frustrating!) in a book that is supposed to be about aliens and aging.
But it is not just the way the abortion issue is presented while giving barely a nod to opposing viewpoints, nor is it the fact that other social issues are presented in the same way (e.g., religion as a superstition that we'll eventually grow out of as a species) - that is not my only or primary objection to the book. It is the way these ideas and their "debate" are presented that I find most heavy-handed and offensive: these views (and the token counterpoints) are done by the protagonists who essentially agree with each other and whose views are later supported (even validated) by others. There's a definite lack of a sincere attempt to present the issues with full disclosure, and therefore without a fully comprehensive "answer" or conclusion.
For example, "every child has a right to be wanted" is presented as the ideal viewpoint in the abortion issue, without acknowledging that a right to life might be superior (not to mention foundational) to merely being wanted.
As I said before, what I perceive as shortcomings of this book may be due to my personal conservatism vs. the author's liberalism, but this is *my* review after all, and this was *my* reaction to the ideas presented in this book.