The only reason I can see for Ross moving to Munster would be because he's from there (good reason as it is). He'll get the same money at Leinster as he would at Munster and, without wishing to be blunt, has more of a chance of winning trophies at Leinster at the moment. Since moving to Leinster he's become an international first choice 3 (his two garbage caps against the USA and Canada don't really count- Niall O'Connor was on the bench then FFS). I'd be delighted if he stays.
I was just taking the **** about Stan Wright moving to Munster but he's a better option than any of Hayes, Buckley, Borlase and Archer. He'd improve the team without being a dominant scrummager.