When Samsung released their quarterly earnings report last week, they declined (as usual) to list the actual number of smartphones they sold. That, as you might expect, led to a bit of speculation as to who was really the biggest smartphone maker in the world. While Samsung definitely passed Nokia to become the world’s largest mobile phone maker overall, there was some question about whether they had passed Apple to become the largest smartphone maker. While one analytics firm held that they had only sold 32 million smartphones (coming in a close second behind Apple’s 35.1 million), another report estimated that they’d sold 44.5 million units, passing Apple by a sizeable margin.

Now another voice has weighed in, and it appears that Samsung really does sit atop the smartphone market. A report released today by IDC estimates that Samsung shipped 42.2 million smartphones in the first quarter, beating Apple by just over 7 million units. Samsung’s surge to take the top spot represents a remarkable 267% growth over the first quarter of 2011, when they sold only 11.5 million smartphones.

Interestingly, of the top five smartphone vendors, only Apple and Samsung experienced year-over-year growth. The other three – Nokia, RIM, and HTC – suffered badly in the first quarter of 2012. Nokia, which posted a $1.7 billion loss for the quarter, sold 50% fewer smartphone in the first quarter of 2012 than in the first quarter of 2011. Meanwhile, BlackBerry maker RIM, which recently made news for a fairly ridiculous PR stunt, sold over four million fewer BlackBerrys in Q1 2012 than in Q1 2011.

IDC’s report also includes a chart tracking the changes in market share among the top five smartphone vendors over the course of the last year. While Apple suffered a dip in market share during the third quarter (the quarter in which the iPhone is usually released), it surged back in the fourth quarter, following the October release of the iPhone 4S. Samsung’s growth, on the other hand, was fairly steady throughout the year, though it leveled off during the third quarter. The other three of the top five, however, showed a steady downward trend, each finishing the year well below where they started in the 2011.

If trends like this continue, it’s pretty clear that the smartphone market will ultimately become a two-horse race between Apple and Samsung. In fact, it’s arguably a two-horse race already. With BlackBerry 10 on the way and the Nokia Lumia 900 just released, there’s a possibility that RIM and Nokia could get back in the game (with Nokia possibly bringing Windows Phone along for the ride), but otherwise the smartphone market appears to be coming down to Apple and iOS versus Samsung and Android.

What do you think? Could Nokia or BlackBerry recover their losses in the near future with BlackBerry 10 and the Lumia 900? Let us know in the comments.