Well, the author of this article seems to think so. Granted, she doesn't explicitly refer to the kipping pullup in her article, but this photo (quite plainly borrowed from CrossFit Santa Cruz), along with its caption, conveys her message loud and clear.
Most CrossFitters utilize the kipping motion in their workouts whenever the WOD calls for the pullup, unless otherwise stipulated (for instance, the L-pullup). This is due to a variety of reasons. Without getting into the hard science of biomechanics and movement patterns, just by watching someone who kips, it's easy to see that kipping is efficient. Basically, you make use of the posterior chain to propel yourself upwards and over the bar, instead of just relying purely on back and arm strength. By utilizing major muscle groups, you fatigue less quickly and are thus able to knock out more pullups, and at a faster rate. This is particularly germane given the nature of CrossFit WODs, where the basic goal is to do more work in less time.
Here's what the good folks over at CrossFit HQ have to say about the kipping pullup. You know it's worth something when it gets its very own blurb on the CrossFit FAQ section! Read the threads mentioned for an in-depth analysis and critique of the kipping pullup, and why it takes pride of place as the de facto CrossFit pullup.
Personally, I treat the kipping pullup and the dead hang pullup as two discrete exercises. Sure, there's definitely considerable skill transfer between the two, but being able to knock out 30 kipping pullups in a row doesn't necessarily mean you'll be similarly good at dead hangs.
In fact, it's pretty common to be able to kip till the cows come home (since a big part of the kipping pullup revolves around mastering the rhythm of the kip), yet struggle to bust out even two or three strict pullups. I've also seen people (usually the military kinds) who are excellent at dead hangs but somehow always manage to bungle up the kipping motion and end up preferring to rely wholly on their lats to see them through a brutal pullup workout. On that note, I don't have a particularly good kip myself - for the longest time ever, I somehow managed to lose my rhythm and ended up having to take an extra swing every five or six reps in order to restart my kip. This frustrated me to no end because it didn't do anything to help my focus during a balls-to-the-wall workout. Simply, the kipping pullup is more about practice and mechanics, than it is about raw strength.
In all honesty, I haven't been working my kip as much as I'd like to, primarily because the gym where I work out isn't equipped with the minimalist pullup bar structure that will allow me to do kipping pullups. (Jeez, just think how much money and space they'd save if they skipped the fancy-schmancy Cybex and Hammer Strength leg adductor and rotating oblique machines with butt cushions and seatbelts in favor of a bulletproof monkey bar structure. But that's another rant altogether).
It's all Nautilus Power Towers here (where the grips on the bar are excessively thick and too widely spaced apart, and I can't launch myself into a swing for fear of banging my knees into the back pad for knee raises). There's a lone power cage with a straight pullup bar across the top beams, but it doesn't look as though it's sturdy enough to handle kips either. So I've mainly been working my dead hang pullup, while using a wider and thicker grip. I'm thinking that will definitely translate into some gains with regards to my dead hangs on the standard-width 1" pullup bar.
I was at the Black Box (CrossFit NYC's sweet digs in the middle of Manhattan) last week and was overjoyed to see one of those no-frills pullup structures. I immediately tried a couple kipping pullups to see how they felt and was kind of surprised to see that I could easily knock out ten or so before my rhythm got wonky and I had to swing in between. So that was nice.
Anyway, I think there's value in working all sorts of pullups. Strict dead hangs, kipping, weighted, L-pullups, the list goes on. I respectfully disagree with the people who condemn kipping pullups as "cheating" pullups, because it really all depends on what your goal is. If you want to isolate your lats and build back strength, do strict pullups. Even better, do weighted and L-pullups (the latter are particularly challenging). The military is pretty firm on their no-kipping rule during fitness tests so there is definite value in working on strict pullups.
However, if you're looking for maximum power output in as short a time as possible, kip as though your life depends on it. From a CrossFitter's perspective, just do whatever the hell it takes to get above the bar if you're racing against the clock. Nobody's going to question your kip if it gets you a two- or three- minute "Fran" like the best of the CrossFit beasts.
Both forms of pullups have their merits and I don't see why any athlete ought to eschew one in favor of the other. Taken together, I daresay the benefits you'll get from working on both will be pretty darn amazing.