Maybe before, but right now a typical txout in a generate looks like:
"out":[
{
"value":"50.24250000",
"scriptPubKey":"OP_DUP OP_HASH160 740ecaf436d5867903c722d783fc994c25a29b15 OP_EQUALVERIFY OP_CHECKSIG"
}
]
Hmm. I checked latest bitcoin code looks like it is still paying to public key. Are you sure this coinbase output is generated by bitcoind not some pool's modification?
Yup, blocks generated entirely inside the standard client do indeed push a key and OP_CHECKSIG.
But, I don't think that many blocks end up in the chain using the standard client's CPU mining capability or getwork RPC calls. Maybe I'm wrong about that, but none of the random blocks that I clicked on in blockexplorer a while back were built using just the key and OP_CHECKSIG.
And of course, as soon as I type this out, I click on a block from Slush, and sure enough, it is using key + OP_CHECKSIG. So maybe it isn't quite as rare as I thought.
Maybe I'll turn my spare GPUs to cracking ECDSA when I convert to ASICs.