If the early reports of ease of porting are true they'd be daft not to. Even if they didn't make a dime they'd know whether the audience is there or not for future titles. I suspect it would get enough interest to at least cover port costs so if I was RS I'd figure "why not" and give it a go.
If I was Nintendo I'd seriously consider a little incentive to encourage RS to do so as well - if they want a share of the PS3/360 demographic they have to get titles like this and they have to make them sell.
The PS2 showed you can have a single console catering to vastly different demographics, from people just playing Singstar and using dance mats to those playing GTA and mature rated games and everything in-between - that's what no console have achieved this gen so far and a keep requirement for any chance to dominate at all.
Try to be reasonable... its easier than you think...
