Symbian and Microsoft announced plans to create smartphones using single core rather than more expensive dual-core architectures within a few days of each other this past week. The idea is to put these generally expensive yet feature-rich handsets within reach of more consumers.

For current market leader Symbian, that means a 3G phone reference design using Freescale's single core modem targeted to run Nokia's S60 (formally Series 60) interface and cutting licensing fees. Microsoft, on the other hand, ported a previously available Texas Instruments feature-phone chipset to its Windows Mobile platform. Smartphones built on both solutions won't ship until 2007.

When they do, Symbian's new handsets will target the mid-range market, while it appears Microsoft may have something decidedly different in mind; perhaps enabling Windows smartphones to hit - or start to come close to - the $100 sweet spot, according to CEO Steve Balmer.

Balmer told Reuters at 3GSM in Barcelona, Spain this week, "I think it will take a year or two before we get to $100 type offerings (of Windows Mobile devices). I may be wrong, but not by much."

A hundred dollar smartphone is a holy grail of sorts to carriers looking to increase average revenue per user (ARPU). Handsets with advanced operating systems have proven higher earners because they encourage subscribers to use content and data services— watch TV, snap pictures, send messages, stream music, etc.—more than traditional feature phones.

If true, 'cheap' Windows smartphones would go a long way towards helping the software giant achieve The Diffusion Group's prediction that it would become the smartphone leader by the end of the decade; with 29 percent of the market, followed by upstart Linux (26 percent) and then Symbian, down to 22 percent from today's dominant 51 percent.

(Mobile Linux received a boost this week when PalmSource returned from limbo with a full-scale open source smart device OS, ACCESS Linux Platform (ALP) and application framework (codenamed) MAX, and Trolltech released Qtopia 4, an upgrade to its own Linux platform for wireless devices.)

Smartphones will account for a much larger percentage of the worldwide mobile phone picture by 2009. As Balmer said regarding his company's mobile handset platform, "The situation today is that a very small percentage of the market is smartphones. Our relevant share is not our share of the overall market, but of the smartphone market. And the smartphone will be a very large share of the total market."

In-Stat reported in January that 31.5 million smartphones sold last year, up from 18 million the year before. By 2009, it says that number will increase to 115 million. 825 million mobile phones shipped in 2005, according to IDC. And many analysts predict 2009 will be the year we see one billion handsets ship.