unlocks dont come from achievements anymore, they are handed out randomly. That's why when u load up TF2 you will see a big list of idle achievement servers, with people going afk over night on them to get the unlocks.
Cheers, but

Was playing the other night and still going for achievments to try to get stuff. Then I got given something randomly which I didn't take any notice off or realise what it was. WIll go and try to find this suitcase thing.
Played with OcuK Gord and had a great time as a medic/attack combo, and generally destroying the other team





. Played for 7 hours since the update and nada, nothing for them, just got the sandman randomly with the new unlock system but the other 2 unlocks I got were from achievements. 1 achievement for 7 hours of play, appalling, I've got 9 or 10 achievements now for the spy which would mean at least milestone one if it had unlocks from achievements.