Anything is fine in moderation yes, however use common sense as starting them too young on something which produces such a dopine hit (the same as TV etc.) and it could have a greater effect.
I have no expertise on this subject... here comes the necessary "but" ... HOWEVER, I personally think TV and video games are a waste of their time at this age and can only really stifle their development, I think they can learn more playing with mum and dad than plonked in front of the TV that's for sure. When they're older and enjoy problem solving etc then it might be a better time to introduce gaming - it might nurture at that point rather than hinder.
As always though, I've no idea what I'm on about and each to there own.
Anyways, my eldest turns 2 tomorrow so time for Dada Gorilla to sign off and figure it all out.