Are Samsung and Google on a collision course?

(MoneyWatch) Samsung has created the biggest hit among Android devices. Although the Galaxy S4 launch last week may have failed in a number of ways -- TechCrunch called it "baffling, overproduced Broadway-style show," while CNET said it was "tone-deaf and shockingly sexist" -- the Galaxy line of products has sold well.

Yet there's an underlying tension between Samsung and Google (GOOG), which makes the Android operating system that powers the Galaxy devices. The companies are vying for brand supremacy, and each wants to be the name that consumers remember when they purchase smartphones or tablets. And if they can't both win, there's a good chance they will eventually go their separate ways.

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Although Samsung no longer discloses the number of smartphone units it sells, analyst estimates put it as the only major rival to Apple's (AAPL) iPhone line. The competitive pressure is enough to make Apple visibly sweat right before the Galaxy S4 launch and then react with a "Why iPhone" webpage and email immediately after to slam Android-based units.

Apple equity analysts largely see the S4 as an evolutionary step that could help Samsung maintain its momentum and potentially overtake Apple in the high-end smartphone market. That's good news for Google, but only indirectly. The problem for the search giant and mobile operating system vendor is that Samsung has ambitions beyond Android.

Google executives are already concerned that Samsung, which has roughly 40 percent of the Android smartphone market, is becoming too dominant. Reportedly, Google's purchase of Motorola Mobility last year was in part an attempt to keep Samsung in check.

In the meantime, Samsung already plans to release some phones this year with its own operating system Tizen, rather than Android, and at least one will be a high-end model. Samsung could also pull an Amazon and create a new version, or fork, of Android, moving in its own direction. And given that Samsung has 327 carriers in 155 countries that will carry the Galaxy S4, that is a lot of market presence it could leverage.

Much of the focus at the S4 launch was on new Samsung offerings, while downplaying competition from Google services, as Evan Niu noticed at MotleyFool:

Instead of talking about Google Play and all the types of content available from the search giant's repository, it showed off Samsung Hub, an integrated storefront for digital content like music, videos, books, games, and more. The new S Translator is exactly what it sounds like, and can potentially replace Google Translate. Forget Google Now and spoken turn-by-turn directions in Google Maps, that's what the new Galaxy S Voice Drive is for.

That's not to say that Google's services are gone, just that Samsung is clearly pushing its own instead. These are just some of many examples where Samsung is actively replicating Google offerings (sound familiar?), and are the first signs that Samsung isn't exactly happy with the status quo and wants more control of the customer relationship and experience than it currently has.

Of course, it makes sense for Samsung to push its own business agenda. But that agenda is not the same as Google's. Should Samsung eventually develop, partner with or buy a viable content service, it could find little use for maintaining a good commercial relationship with Google.