At MIX10, a 3 day conference for web designers and developers that started yesterday-Microsoft introduced several features of their latest Windows Phone 7 Series OS targeting developers of applications and games.
The biggest highlight was the new Window Phone Marketplace which has replaced the previous Windows Marketplace for Mobile. Simply put, it is a place where you can find everything you are looking for. Regarding this new version Engadget comments as “The Marketplace has evolved from an app store to a content “destination,” housing apps, casual and premium Xbox Live games, music, and customized carrier stuff in one spot.” and also “Windows Phone Marketplace appears to take some of the best parts of the App Store and the Android Market and throw them together into a hodgepodge”

Windows Phone Marketplace for Developers:

- In the MIX10 event Microsoft has introduced developers how to build apps and games for Window Phone 7 series and how to work with development tools.
- Microsoft have partnered with Silverlight and XNA to provide framework for developers to craft applications and games for Windows Phone 7 series (WP7S).
- Windows Phone 7 series development tools for Visual Studio and Microsoft Expression Blend (a UI dev tool) free to download here.
- It’s up to the developer to decide how the trial works.
- Marketplace membership for developers still costs $99 a year.
- If a developer wants to post a free, ad-supported app, they’ve only got two hurdles: the $99 fee and approval by Microsoft, reports Engadget.
- No fees for developers to update their applications.

Windows Phone Marketplace for Consumers:

- Free trial of applications before buying them.
- Support for credit card purchases, operator billing, and ad-supported content.
- “Panoramic View” where you can browse categories and titles, see featured items, and get details with ratings, reviews, screen shots, and pricing information. Purchased apps can be pinned to your Quick Launch screen, according to Engadget.
- The only official way to get apps on a Windows Phone 7 Series device will be to download them from the Windows Phone Marketplace.
- Purchases are tied to your Live account, not to your Phone making it possible to uninstall purchased apps and re-download them at a later time.
- No additional download after the trial expires; the game just unlocks if you choose to buy it.

Windows Phone Marketplace demo

The drawbacks

- No multitasking.
- The Zune Client is used to browse Marketplace but it is a Windows-only software.
- Windows Mobile 6.x Apps won’t work.
- No development on Mac.

Windows Phone 7 Series in general

Few highlights:

- Native DivX support through DivX6.
- Only two resolutions available as 800×480 WVGA resolution and later 4480 x 320 HVGA resolution for Windows 7 handsets, however,  for developers it is good news as they only have to write for two screen sizes helping them keep developing for the platform relatively simple, comments Gizmodo.
- Among the companies who are ready to roll out new applications include WeatherBug, Citrix Systems Inc., Clarity Consulting Inc., Cypress Consulting, EA Mobile, Fandango Inc., Foursquare Labs Inc., frog design inc., Glu Mobile Inc., Graphic.ly, Hudson Entertainment Inc., IdentityMine Inc., IMDb.com Inc., Larva Labs, Match.com LLC, Matchbox Mobile Ltd., Microsoft Game Studios, Namco Networks America Inc., Oberon Media Inc., Pageonce Inc., Pandora Media Inc., Photobucket Inc., PopCap Games Inc., Seesmic, Shazam Entertainment Ltd., Sling Media, SPB Software Inc., stimulant, TeleCommunications Systems Inc., Touchality LLC and Vertigo Software Inc. among others, reports  Ubergizmo.
- Finally, according to Gizmodo’s John Hermann, the biggest challenge to WP7S is (considering the late launch of the handsets later this year):
1) “Without an audience to sell to, why would developers invest in creating complicated apps? And if a platform doesn’t have these great apps, why would people switch to it?”
2) “By the end of this year, the platforms WinPho7 series will be competing with—namely iPhone and Android—will be even more deeply entrenched with users than they are now.”