I recently finished Lee Smolin's Time Reborn: From the Crisis of Physics to the Future of the Universe (2013). Smolin is my favorite among the prominent theorists who write for a popular audience. He's an excellent writer, nearly as good as Leonar Susskind (The Cosmic Landscape) at explaining, though at the end of the day, the string theories Susskind explains so well are nonsense. (Smolin made the latter point so well in his The Trouble with Physics, which I also enjoyed.)
Time Reborn was a worthwhile, educational read. What sets Smolin head and shoulders above the rest is that he's an iconoclast and doesn't mind taking an unpopular view. So among other causes, he's sympathetic to Bohmian mechanics(!), and (much more importantly) very clear that there must be a universal reference frame and a single time that unifies the entire cosmos.
Smolin is full of good insights and clearly sees some of the great weaknesses of modern physics, and especially with the field of cosmology and fundamental forces. Smolin sees very clearly that time has been flattened to a spatial dimension, or even a mere parameter, in physics. His discussion here is excellent.
While Smolin is the most philosophical of any physicist who writes for a popular audience, he's definitely not a philosopher. The major problem with the book is that he doesn't consistently apply his own critique to himself—not that that has stopped any modern philosopher from being a philosopher. (Come to think of it, maybe Smolin is a philosopher!) Smolin's ambition is to restore the meaningfulness of time back to physics. A great ambition! But he baffles himself by not having a clear philosophical account of what time is, so he cannot know what it means to restore time, still less can he know whether his ambition is even possible.
His idea is to do away with "timeless" physical laws, so he posits that cosmic laws are evolving and over time come to assume an habitual form. Thus earlier on, things are less determined and they grow more determined as the universe gets older. But if you take a step back, you notice that that this principle is itself a "law" and somehow it escapes Smolin's ban on "timeless laws." He grudgingly acknowledges as much in a later chapter, but doesn't (and can't) do anything to fix the problem.
Actually Smolin's quest for timeless laws is something of a fool's errand. (Not that Smolin is a fool; I think he's just working with a diminished set of principles since he's constrained to the twelve-tone system, so to speak, of modern philosophy, and simply lacks the full pallet of expression.) The point of our thinking philosophically/scientifically is to come up with laws that are always true, that is to say, timeless. But they're timeless in a way that's different from the timelessness that Smolin rightly rails against.
Modern thought patterns itself after Descartes, so without abandoning the sandbox of modern thought, one simply lacks the tools to think about time in the right way. That would be to come to conclusions about time that are always true (i.e., in a properly timeless way), but while capturing time's true nature, a way that is true to the "becoming" of time and the unfolding of real novelty in the universe. Tragically Smolin, as great as he is, is like the proverbial fish who can't notice the medium in which he swims.