> Does anyone know when/if Gates will ever pay taxes on his $51B?
Most of his net worth is in unrealized gains on MSFT stock. He has a policy of divesting 1% of his holdings per quarter, so he is continually (but for another 20 years or so!) paying taxes on his gains.
> What is the loophole he uses to get out of paying tax on this?
In the US at least, there's no such thing as a wealth tax; you only pay taxes on certain kinds of transactions. A capital gain is one such kind of transaction.
/jordan