To be honest, I'm only aware of 2 Avalon units out in the wild. ASICMiner has a big setup at about 3TH. BFL are currently at the bumpping phase of the project so... I don't think anything is going to change much in the next week or two.

However it will change dramatically when BFL starts shipping, since their first batch (of appx 6-7k chips) will account for 40TH dropped onto the network. (approximately). Then a soon to follow batch (of abbout 10 days delay) will drop another 40-50TH onto the network. Maybe more.

Pretty soon 4.5GH will look like 250MH.