If ever there were confirmation that the smartphone market is now a two-horse race, it came with the latest IDC Mobile Phone Tracker figures, which the research company has regularly generated since 2004. Nokia had topped the charts ever since – until now, when it lost its crown for the first time ever.

It was Musical Chairs for everyone as the smartphone leaderboard shuffled around dramatically compared with a year ago. Samsung, for example, jumped from an 11.3% market share and 11.5 1Q11 shipments to a 29.1% market share and 42.2m unit shipments – a 267% increase. Apple, by contrast, jumped from 18.3% market share and 18.6m units shipped, to 24.2% market share and 35.1m units shipped – an increase of 88.7%.

Beyond those two vendors, the story was one of annihilation: Nokia's market share dropped 50.8%, Research In Motion dropped by 29.7%, and HTC dropped by 23.3% while the category known as "Others" was retained around one-quarter of the market but saw 59.6% growth overall.

All these numbers point to just one thing:, there has been a massive reshuffling in vendor market share over the past year as the market responded to Samsung's aggressive push into the smartphone market – at the same time rejecting proprietary platforms, and efforts to save them. Both Nokia and RIM have been pushing many new models into the market – with Nokia delivering well-received devices based on Windows Phone 7 (WP7) and RIM dropping teaser after teaser for its BlackBerry OS 10 software – but the figures all but confirm that ever-fickle consumers are quickly losing interest.

Another particularly interesting result from the latest IDC figures comes in the decline in demand for units from HTC. For a while there, HTC had built itself quite a nice little bit of momentum, on the back of what people generally argue is strong hardware and nice software. HTC's new One X smartphone has been lauded as a game-changer, and it came out too late to be factored into the Q1 IDC figures.

Whether or not the One X sells well, it's questionable whether a single mobile vendor can claw back major market share based on a single hero product. Apple has done it, of course, but the iPhone has brand cachet and is part of a much larger ecosystem that HTC is only starting to unflinchingly copy build out.

The company is so serious about turning its HTCSense.com cloud services into a real contender that it wiped all of its existing users' data on April 30, then shut down the domain until a future date to be determined while it revamps its cloud offering. Critics were scathing but believe those users that aren't left with a bad taste in their mouth by being left holding the bag, may do well as HTC redoubles its efforts to reverse its flagging fortunes.

It's not clear, however, whether or not HTC can single-handedly reverse the company's flagging fortunes this way. The company took an early lead in the Android market with its well-received Sense interface, but Sense obviously hasn't kept Samsung at bay. HTC's efforts to diversify, by offering WP7 devices, have fallen relatively flat – and WP7 may fade into irrelevance for HTC as Nokia's blood pact with Microsoft pays off with critically-lauded, if not exactly world-changing, phones like the Lumia 800 and upcoming Lumia 900.

The Q2 Mobile Phone Tracker data will be quite telling, both because they will show whether Samsung can keep its market momentum; whether Apple will keep abreast of its biggest rival; whether HTC can bolster its fortunes enough to avoid following Nokia and RIM into despair; and whether Nokia can breathe enough life into its smartphone business to make it valuable enough for Samsung or HTC – or even Microsoft or Facebook – to eventually purchase. These are the endgames behind the numbers – and with the stakes so high, anything is possible.