Regardless of how much money Android has generated (or, more accurately, hasn’t generated) for Google, there can be little doubt that Google is pleased with the fact that it owns the second most popular mobile OS in the world.

But the popularity of Android isn’t without its problems. Fragmentation, for instance, has always been an area of concern for developers and handset manufacturers, if not for Google.

Fragmentation in and of itself, however problematic, isn’t Android’s biggest problem though. So what is?

Increasingly, it looks like the answer to that is getting the newest versions of Android onto devices. As Mashable’s Stan Schroeder observes, nearly 64% of Android devices are running a Gingerbread (Android 2.3) variant. And just over 23% are still running Froyo, Android 2.2.

As you might guess, that’s bad news for Ice Cream Sandwich (ICS), the latest version of the Android OS. One of the biggest updates to Android since it was first unveiled to the public, ICS was designed to reshape Android, creating a unified experience for both smartphones and tablets. For obvious reasons, that goal is really important to Google, which is hoping that it can do in the tablet space with Android what Android has allowed it to accomplish in the smartphone market.

Unfortunately for Google, a paltry 2.9% of Android devices in the wild are running ICS today. The good news for the search giant is that this figure will almost certainly rise later in the year, as a number high-profile smartphones powered by ICS hit the shelves.

So is the slow uptake of ICS really that big of a deal? Arguably it is. It’s important to keep in mind that the latest version of Android was unveiled in October 2011, nearly seven months ago. That may not seem like a long time, but in the world of technology it is.

Which raises the question: if it takes well over half of a year for the latest and greatest version of its Android OS to gain traction, just how effectively can the company hope to compete with a much more nimble Apple and iOS?