If you hold coins for 2+ years they get taxed under the capital gains tax rates.  The rate you pay is based on your income plus your capital gains, 0% up to a certain amount, 15% after that, and 20% if you are rich.  Ok let me try to explain.

For a married couple the 0% capital gains rate goes up to $72k, less if you are single.  So let's say that your income is $50k.  You pay your income taxes based on that.  Now let's say that you sell some bitcoins for $40k that you bought for $10k.  So that means that you have a $30k capital gains (40 - 10).

So we start piling your capital gains on top of your income.  You take 22 of that 30 to go from $50k to $72k.  You pay 0% on those capital gains.  The remaining $8k is taxed at 15%.

Let's say that you have no income, just huge numbers of bitcoins.  Every year you spend/sell enough to make $72k and live on that.  0% tax rate.

I don't understand how taxes on foreign currencies work, but it seems like it is 23% if you keep good records and 35% if you don't.  Much worse than capital gains.

When you die all capital gains are zeroed out.  So let's say that I buy a bitcoin for $600 and die, leaving it to my son.  Now the bitcoin is worth $100000.  No capital gains on that.  If my son holds it for two years and then sells the coin at $101000 he has a capital gain of $1000, which is going to be taxed at 0%.

So basically capital gains taxes are 0% if you hold your coins long enough and if you don't make too much at your day job.  I think that this describes most people who hold coins now.  If not, there are legal ways to avoid taxes that become feasible when you start talking about big money.