This issue has already been discussed in other threads for this game:
Pandemic Express » Forums » Rules » Trademark Concern
Here: Pandemic Express » Forums » News » Rebrand & Vassel Module Under Development
And Here:Pandemic Express » Forums » Sessions » Version 1.1. the antibiotic resistant strain
There are plenty of examples of games that have borrowed heavily from other games, so I don't think that's any problem. The only objections that so far have been raised are on using the Pandemic name (hitching a ride on the coat tails etc) and renaming will help build an identity, so sooner the better - though obviously its original name IS PROBABLY what brought most people over to try it out. Not sure about the name, sounds like there's a non-dice version out - Maybe Dice Infection or Infectious Dice?