I'm a big fan of the comic xkcd. Its unabashed nerdiness and superior wit combine for some truly great comics. Today's is a brilliant synthesis of his newfound enjoyment of electric skateboards and Mario Kart Double Dash, and an homage to the philosophical and artistic style of Calvin and Hobbes' wagon comics.
Now, I am also a big fan of Calvin & Hobbes. I read and relate to Calvin & Hobbes as I would a religious text. I also respect Bill Watterson's firm desires never to have Calvin & Hobbes parodied (isn't there a better way to show everyone you enjoy hunting than to buy a sticker of Calvin peeing on the word "anti-hunter?"), referenced, or duplicated. As such, even a respectful C&H homage as well-done as today's xkcd is treading on sacred ground and should be subject to intense scrutiny.
Obviously he wanted the characters on the skateboard as entrenched in Calvin & Hobbes' world as possible, to write dialogue like Watterson, and to compose a scene like Watterson. The idea of the strip is great, but I have two major complaints about its execution, where I feel he failed on two counts (and C&H is such sacred ground that I'm splitting hairs finely enough so that anything short of perfection is failure):
First, the strip hits us over the head with what it's trying to accomplish. Its reference to "building character," obviously Calvin's dad's mantra, is said in earnest, and exists only as a red flag in case you didn't follow from the artwork yet. Additionally, it uses the word "philosophy" in lieu of actual philosophy. Not only is that lazy, forceful writing, but it's *telling* us what it's doing, not *showing* us, which is jarring and wrong in the context of how the wagon strips played out artistically and textually.
Second, it misunderstands the Hobbes duality. While Hobbes' true nature may be up to interpretation, it is very consistent: Hobbes is always in stuffed tiger form when there are other humans around. Calvin's world is his alone.
I disagree with the argument that this strip just lets us know that xkcd/Randall's mentality is closer to that of Calvin than that of the real world. However, discussions of Python/C, skateboards, and Mario Kart firmly ground it in our own human world, where Hobbes would be in stuffed form.
That said, this is still a very moving strip. In my admittedly picky opinion, however, it just falls short of a goal within its reach. A truly respectful tribute to Calvin & Hobbes should be done perfectly (i.e. consistent with the C&H world) or not at all. Just remove the line about "my philosophy" or replace it with an actual philosophy, and draw Hobbes in his stuffed form, and this would be it.