In trying to keep itself in the mobile spotlight, Microsoft’s Robbie Bach is making an appearance this week at CTIA to announce a handful of things, ranging from more details on its upcoming Windows Marketplace for Mobile to content deals its working on with Facebook and MySpace—and in an odd flashback to the 90’s—designer wallpapers. Even though Bach won’t appear on the stage until Thursday, Microsoft (NSDQ: MSFT) is releasing the news early. Bach’s appearance follows Microsoft’s participation at Mobile World Congress last month, where it announced Windows Mobile 6.5, its Marketplace and MyPhone, which allows you to back-up important information on your phone to the web.

The most important piece of information being released today is that Microsoft will be working closely with the mobile operators on its upcoming Windows Marketplace. Microsoft Group Product Manager Aaron Woodman told mocoNews that they will allow customers to pay for applications by credit card or with their phone bill. In addition, it will allow carriers themselves to also sell content in the Microsoft storefront. Woodman explained it as the ability to “customize a store within a store,” like the “end cap” that’s set aside for marketing a new product in a grocery store.

More details on the generous return policies of the Marketplace; the MySpace and Facebook apps coming to Windows Mobile; and wallpapers after the jump…

The partnership approach by Microsoft is smart. Others, such as Apple (NSDQ: AAPL) and RIM (NSDQ: RIMM), have decided to avoid working with carriers by using alternative billing systems, such as iTunes and PayPal. In doing so, those platforms don’t share a percentage of revenues back to the carrier, but they also be could conceived as a competitive threat to carriers. If Microsoft says it will be allowed to use a carriers bill, it will likely be sharing revenues with the carrier, too, putting it in a more favorable light.

The result might be more carriers selling more Windows Mobile hones—which is what the store is all about. Woodman declined to say what the cut would be for operators. “We aren’t announcing revenue share, we are announcing the functionality…Mobile operators are an important part of the puzzle, and we are going to create opportunities for them.”

Facebook and MySpace: MySpace announced earlier today that it will release an application for the Window Mobile 6.1 platform, and that it will be pre-loaded on LG (SEO: 066570) phones. In addition, the company is partnering with Facebook on a Windows Mobile app. It’s surprising there hasn’t been one to date, but perhaps the wait was worth it. It will allow users to record and upload video to their Facebook profile. The two apps will be available for download at www.windowsmobile.com until the Marketplace officially opens later this year. Other content companies that will participate in the Marketplace launch include: 3deep, Accuweather, AP Mobile, Developer One, EA Mobile, Gameloft (EPA: GFT), Hands-On, Ilium Software, Jeyo, Kinoma, Magmic, Melodis, Namco, Pandora, PhatWare, Resco Mobile Solutions, ShoZu, SBSH Mobile, SPB, and Web Information Solutions.

More App store details: Woodman said they will also be announcing that the store’s return policy will allow for a full refund within 24 hours of purchases. The policy is fairly aggressive. Apple recently got grief from the developer community because of its policy to allow for returns, but still charge developers 30 percent to cover the cost of the transaction. Woodman said if a refund is made, it won’t cost the developer anything.

Wallpapers and personalization: Microsoft is also announcing two partnerships with the Design Museum London and Council of Fashion Designers of America. Based on those relationships, Microsoft will offer a variety of “designer themes,” which will customize everything from the phone’s wallpaper to the scroll bar. The first partnership is with Isaac Mizrahi, which has designed for Target and Liz Claiborne. In screenshots provided by Microsoft, the first themes look like a red plaid layered over the Windows Mobile 6.1 screen. Other designers will be announced in the coming months. In addition, Microsoft is launching the Theme Generator later this year, which will allow users to pick pictures from their PC to set as background images, as well as choose colors to personalize their navigation bar, scroll bar and highlighted text.