The future of Nintendo's WiiWare game download service is still very much unknown, but that hasn't stopped the company from greasing the wheels with back room deals meant to entice small and medium-sized developers under their wing.

Their first target? Disgruntled Xbox Live Arcade developers, and in this case the house that Mario built isn't playing its usual game of family friendly fun -- they're playing hardball.

U.K.-based Develop magazine reports that as Nintendo prepares for the North American WiiWare launch on May 12, it is "actively briefing studios" on what makes the service such a great platform to make titles for.

According to anonymous developer sources cited by Develop, Nintendo looks to be stressing the fact that their service won't be flooded with retro titles and that developers can get a better royalty payout on WiiWare than on Xbox Live Arcade or PlayStation Network.

In February, Kotaku broke the story that Microsoft had cut developer royalty rates on XBLA games by as much as half. Develop expanded on that with information that showed first-party Xbox Live Arcade royalties were "restructured" from 70% to 35% for games that generate less than US$4 million in revenues. The rate approaches 50%, however, when sales figures go over $4 million.

Said one anonymous studio head: "Nintendo has made it very clear to us that we'll not only be making a better royalty rate from WiiWare games, but we'll also have a better chance of selling games - the service won't be clogged up with the retro titles that have blighted the chances of many independent studios on Xbox Live Arcade."

Another WiiWare developer said the lack of classic titles on XBLA meant they were not developing for the service because it was "full of ****."

On the other hand, with 10 million registered members Xbox Live is also full of money, and has been a very lucrative venture for Microsoft so far.