Simple capital gains tax question?

I'm not an accountant but was asked this question today and just flat out didn't know the answer.

It's my understanding that long term capital gains are taxed at either:

A) your current income tax rate if below 15%, or
B) 15% if your income tax rate is slightly above 15% (say 25% or so), or
C) 20% if you have a very high income tax rate (say 39%). Also believe you can be hit with an additional 3 or 4% surcharge if in this category.

I'm sure that is a little wrong (or perhaps a lot).

So let's say someone is making an income of 70,000 and only has an income tax rate of 25%. If he were to realize a long term capital gain of $10,000, that capital gain would be taxed at 15% correct?

now, let's say that same individual is still making an income of 70,000 and still has an income tax rate of 25%. If he were to realize a much larger capital gain of $1,000,000, would he still only be taxed at 15% for his capital gain since that is what he would be taxed at for capital gains based on his income tax rate? Or do you factor in the fact that he's realizing a $1,000,000 long term capital gain, and therefore his income tax rate would increase to 39% which would then trigger the higher long term capital gain tax rate of 20%?

Short term cap gain is taxed @ whatever your tax rate is.

Long term cap gains tax rate:

Your tax rate is 15% or less, 0%
Your tax rate is 15% - 35%, 15%
Your tax rate is >35%, 20% (starting 2013)

Small gain or big gain is irrelevant.

Also, they will start to impose SSI tax on some of cap gains starting 2012. Thank you Obama.