Microsoft wanted 600 applications filling its Windows Marketplace for Mobile on its first day of release, Oct. 6. The idea was to give Windows Mobile 6.5, its smartphone operating system debuting on the same day, a sizable ecosystem with which to begin challenging Palm, Apple, Research In Motion and other players in the mobile-device space.

That didn't happen--but Microsoft can claim that the applications present for download represent a broad swath of functionality for the majority of users.

"Microsoft is pleased today to introduce 246 quality mobile applications initially in Windows Marketplace for work and play, with more than 753 ISVs (independent software vendors) worldwide on board to continue building out the catalog," the company wrote in an Oct. 6 statement.

Specifically, the available applications include Facebook, MySpace, Netflix, Twikini, WunderRadio, and Zagat, as well as games like Sudoku and Pac-Man.

Some other interesting details about the phones emerged during a presentation by Robbie Bach, president of Microsoft's Entertainment & Devices (E&D) Division, at Microsoft's Open House event in New York:

• Microsoft is planning on having 30 new phones running Mobile 6.5 by the end of 2009. (For the Oct. 6 launch, a handful of phones manufactured by HTC, Sony Ericsson and LG Electronics will be among those with the operating system installed.)

• Redmond has emphasized filling Marketplace, with "hundreds of applications" potentially coming soon.

• Users can re-download purchased applications up to five times. A useful feature in case your computer unexpectedly decides to fry.

• Mobile 6.5 brings the cloud to the forefront of the phone experience. The My Phone feature enables users to back up their files, simplifying the restore process if they lose their smartphones. Coolest feature: If users misplace their phones nearby, they can sign online and force the device to ring loudly for 60 seconds, even if it had previously been set on silent or vibrate.

My colleague Jeff Cogswell has already tested Windows Mobile 6.5 on the AT&T Pure--his review can be found here. Microsoft is rolling the dice big-time on whether it can succeed in the mobile operating-system space; and while some have doubts that it will be able to substantially eat into the market-share of other smartphones on the market, they at least seem off to a relatively robust start.