Questions, answers, and resolution of disputes regarding the online rating in HoMM5.

Is there currently an online ranking system for Heroes of Might and Magic V?

Yes, there is a ranking system for duels:

/topic/3834/

Also, the calculation formula has been slightly modified, and some items have been added to the rules:

/topic/3836/

As for Ranked Tournament Arena (RTA), I'm not sure; it seems they were also planning to keep track of scores.

But in general, no one is dueling anymore; apparently, everyone (including me) has gone out into the sun, swimming, etc. And that's probably a good thing :D