Forgive my ignorance, but if the address (Satoshi's genesis address) contains the unspendable BTC, does is mean other Bitcoins that get there become unspendable as well? Of course, these coins aren't likely to ever be accessed anyway, but, assuming Satoshi is alive and didn't lose access to anything, would Satoshi even be able to use those coins? pooya87 says it's possible, which gives some hope these coins aren't just burned.
IMO, if one has such money to spare, it would be better to donate it to a good cause instead of burning. I don't think it was done by mistake, though.
Well, let's clarify something. It doesn't matter if it's Satoshi or if it's me (let's say), but anyone who have the private key that unlocks the genesis block address, can spend the money found in it.
Therefore, if you decide to send BTC there, the only way to be spent, is if someone has the key to this address.
If Satoshi is a person and if Satoshi is alive and if Satoshi owns the key, then they could definetely spend the BTC you send there.
Thus, it's definetely not verified that this amount of BTC is burnt.
If you want to "burn" some bitcoin you can generate an address, send the money there and ELIMINATE the private key that has access to it.