The race is on. According to the most recent data from The Nielsen Company, the Apple iPhone and RIM Blackberry are enmeshed in a statistical dead heat with 27 percent of smartphone market share in the U.S. Twenty-two percent of smartphone owners have devices with the Android operating system.

But Google’s Android platform isn’t out of the running just yet. According to the October Nielsen report, when mobile users who planned to upgrade to a smartphone in the next year were asked about their next phone, Apple’s iOS and Android were tied for “most desired” operating system. Among users planning to get a new smartphone, current smartphone owners showed a preference for the Apple iPhone (35 percent), while 28 percent of both smartphone and feature phone planned smartphone upgraders indicated they wanted a device with an Android operating system as their next mobile phone.

What’s more, Apple’s iPhone and devices with the Android operating system were the “most desired” among likely smartphone upgraders, with Apple showing a slight lead among those age 55+ , 18 to 24, and 25 to 34. There is also a gender divide among today’s smartphone owners: Nielsen reports that women planning to get a smartphone are more likely to want an iPhone as their next device, with slightly more males preferring Android.

As for smartphone usage, although originally developed as a consumer product, the iPhone is fast finding its way into the hands of time-strapped CEOs and harried employees. UBS AG, Switzerland’s biggest bank, is considering allowing its staff to use iPhones for company messaging. And mutual funds provider Vanguard Group, Inc., is also testing the iPhone with a handful of its employees.

But regardless of who wins the race for most popular operating system, one thing is for certain: today’s feature phones are dying a slow death. Nielsen reports that the share of smartphones as a proportion of overall device sales has increased to 29 percent for phone purchasers in the last six months and 45 percent of respondents to a Nielsen survey indicated that their next device will be a smartphone.