Today the newswires are all-a-flutter with the brilliant success of Nokia’s Ovi Store and the proliferation of apps that have flooded to the struggling mobile giant. With a jump to 5 million downloads a day from last years 1 million downloads a day, they’re seeing a huge leap in acceleration with user adoption. Much of this windfall is being touted to the release of numerous Symbian OS devices by Nokia, but it’s overshadowed a bit by the looming future of Microsoft devices on the Finnish mobile manufacturer’s horizon.

February of this year saw the inking of a major alliance between Nokia and Microsoft and the expectation that after this development cycle, most (if not all) of the mobile devices coming out of Nokia would carry the Windows Phone 7 OS. In fact, Microsoft has subsidized the development of WP7 Nokia Phones with a $1 billion booster shot. All these factors—and the worthwhile success of the Ovi Store in the Symbian market—raise the specter of asking whether or not this success will continue into Nokia’s Microsoft era.

According to a great deal of their developers and publishers who are reaping the benefits of the operator payments opportunities and the greatly increased Ovi Store download rates, few of them are concerned.

"Nokia’s Ovi Store has given our Angry Birds a fighting chance to defeat those havoc-wrecking green pigs and share the joys of clearing levels from every corner of the globe," said Mikael Hed, CEO of Rovio. "We look forward to continuing development for Nokia’s latest Symbian devices and working with Nokia and the future of the Windows Phone platform."

A lot of the various games and apps listed in the Ovi Store do appear to be Flash and Java applications, which means that they may not be difficult to port from Symbian to WP7. Of those appearing in the developer examples include a Flash games developer, Breakdesign, with over 6.5 million downloads; a mobile social-gaming community for Java that reached 1.3 million downloads through the Ovi Store; and a cloud-based intelligent music playlist agent called Moodagent with 4 million users and 4 billion tracks.

The spokespeople over at Nokia also want people to know that they’re not going to withdraw from Symbian and hope to leverage Microsoft’s OS at the same time.

Tero Ojanpera, Nokia’s Executive Vice President of Services and Developer Experience says, "This momentum continues to demonstrate consumers’ appetite for Nokia’s global and locally relevant apps, and will help us plan the future apps store experience for improved and new Symbian devices, as well as Nokia smartphones based on the planned collaborative opportunities with Microsoft.” The Finnish mobile corporation plans to ship at least 150 million Symbian devices in the coming years so at least developers can breathe easy about all of the work they’ve already done in getting prepared for Symbian OS—but they might want to set their sights also on WP7 just to cover their portfolio when it comes to Nokia’s phones.

Right now, Nokia is playing very hard to keep their current Symbian developers happy as they rightfully watch warily as the Microsoft deal starts to come to fruition. They’ve already watched Meego fall to the wayside and probably need a certain amount of assurances that their hard work (and pocketbooks) won’t suffer due to this rapid change in tack.

After CEO Stephen Elop’s “burning platform” speech and the sudden change in direction for Nokia this may become a sticking point for many developers.

The triumph of the Ovi Store brings us a lot of heart for their continued market supremacy but only time is going to tell how it will reflect on the WP7 phones when they arrive.