So if I have 30,000$ in TFSA then 10,000$ is over-contributed....dust the gains from that amount is going to be taxed. An example, cuu at 5$ a share is $50,000 investment income gain...this amount would be taxable under the new tax laws, this is what golfyeti is implying.

You should call the TD guy back up because it is appalling that he would give you such incorrect information.

Not only would the initial over-contribution be taxed at 1%, but the gain would be taxed at 100%. You would lose all the gain and pay a penalty on the over-contribution.

(As an aside you can only contribute to the TFSA once you attain the age of majority and I think that is determined by the province in which you live. So you can't automatically put in $20,000 if you sign up today if you were not the age of majority in 2009.)