I also saw that Middlebrook had a ton but his bowling was 10-1-59-1 and his average is around 40. He did get 50 wickets last year though so he could have potential.
Dalrymple may well be bowling better today as you pointed out and is certainly getting his monies worth havig bowled 35 overs. Key's reached 50 again and must be close to a call up surely.