Apple’s share of tab pie slumps as rivals snatch some tab glory.

The mini iPad line outside Sydney’s Apple Store on Friday. Image credit: Fairfax

The Apple slowdown as consumers held out for the iPad mini put a “sizeable dent” in Cupertino’s commanding marketshare, slipping from 65% in 2Q to 50% in 3Q12, said analysts IDC today.

Android shipments, led by Samsung and Amazon, surged during the quarter, at the expense of Apple.

The iPad grew share by over 25% while Samsung’s rival Galaxy Tab has risen a dramatic 325% rise -y–o- y (just under 20% total share), while No. 4 tab Asus +242.9% (thanks to Google Nexus).

No. 3 tab Amazon also did well in the quarter with almost 10% share, Lenovo too rose .

However, the iPad is still the world’s Number Uno tab and is set for big things in Q4, say analysts, as appetite shifts to the iPad mini, that went on sale here on Friday last, although the usual Apple-esque hyper queues were absent.

Apple sold a whopping 3m iPads (mini plus and fourth gen iPad) on its first weekend of sale (close to almost the 5.1 m rival Samsung shipped over a 3 month period).

 “Now that the new mini, and a fourth-generation full-sized iPad, are both shipping we expect Apple to have a very good quarter,”said Tom Mainelli, Research Director, Tablets at IDC.

However, the mini’s “relatively high” $329 starting price leaves room for Android vendors to build upon their Q3 success, he added.

Samsung shipped 5.1 million tablets worldwide in 3Q12, and “took advantage of an opportunity in the second quarter,” said Ryan Reith, IDC’s Mobile Device Trackers.

Its wide range of tabs with multiple screen sizes and colors resonated with more buyers this quarter.

Samsung’s growth represents the first time a competitor has attained this level of share since the original launch of the iPad.

“Competitors are turning up the pressure on market leader Apple,” says Reith.

But Apple now have a third headache: Microsoft.

“With the recent introduction of a number of Windows 8 and Windows RT tablets, consumers now have a third viable tablet platform from which to choose.”

However, Microsoft and its partners including Samsung, Acer and Asus will have a tough time winning a share with price points starting at $500,” the IDC analyst warned.