Total network hash rate has jumped by nearly 10% to over 154Thash/s since last night. Diff estimated to increase to over 18 million by Sunday.
The estimate is already at 18.5M according to
bitcoindifficulty.comInteresting times

it was at 21.2 when the last diff went up, so 18.5 is pleasing to see
http://dot-bit.org/tools/nextDifficulty.php this one has 19.9 estimate