Growth in the post-PC era may finally be slowing down if the latest report from NPD DisplaySearch is any indication. The analytics firm found that tablet shipments during the first quarter dropped year-over-year for the first time ever.

In the report, NPD found that several brands realized weak tablet sales during the first three months of this year. At least some of the weaker sales were blamed on delayed product launches but we also must take into consideration the possibility of market saturation.

The latter scenario is evident in the chart above from NPD. Specifically, take a look at the huge jump in tablet shipments from 2012 to 2013 and compare that looking ahead. The growth rate is expected to be just 14 percent this year and by 2017, NPD believes it'll be in the single digits.

Larger-screen smartphones, collectively referred to as phablets, are also cannibalizing the smaller tablet market. One change that most expect to see over the coming years is a shift toward tablets with larger screens like Microsoft's Surface Pro 3. NPD predicts shipments of larger tablets will overtake smaller ones by 2018.

NPD still expects overall growth for 2014 but has lowered its forecast from 315 million tablets shipped to 285 million.

Truth be told, hardware makers don't really have too much to worry about until we start to see annual shipment drops. As long as growth is happening, all is well in tablet land.