At the minute I'd be tempted to go for something like:

Denly (averaging somewhere around 45-50, outstanding against India for England Lions)
Godleman (hundred vs Pakistan U19 yesterday and average near 45)
Edwards
Shah
Joyce
Bopara
Rashid
+Mustard/Ambrose
Broad
Mark Davies/Tremlett
Kabir Ali

Other options: Onions? Swann? Sales? Gidman?

Sayers only averages 35 this season and has tailed off in the last few innings, plus he's horribly slow and the international game is faster-paced than it used to be. I'd leave him for some time before he develops some scoring shots! Sidebottom is bound to be picked for the winter tours and I see no need to consider him - he was picked in our team last year and is establishing himself now, and I am eating my hat!

Kabir Ali (50 wickets at 22.13, econ 3.27) has been a revelation in first class games this season, whilst suffering the same old problem of disappearing around the park in FPT and Pro40 matches (see Worcs' matches against Durham for example). It's notable that few English bowlers have averages below 30 in first class cricket this season - the others in the leading averages list being Harmison (53 at 22.33, econ 3.25), Caddick (66 at 22.78, econ 3.21) and Sidebottom (39 at 28.28, econ 2.64) and few overseas professionals/Kolpaks manage the same feat despite the rain and swing-friendly conditions this season. Thus, Ali really stands head and shoulders above any other seam bowling candidates and strongly forces his way in for me, but only for test match consideration as his ODI credentials are poor. I'll continue to push for Davies who has begun to find form after returning from long term injury, just having taken 7/59 for Notts and boasting career figures of 166 wickets at 23.16 in just 50 matches, economy 2.87 and averaging 30.8 this season in 7 games, bearing in mind my comments about the poor performances of bowlers in general ths season.

The keeper decision is tough. Ambrose is doing well and will probably be picked first due to that and his Sussex links, however he does boast a good average. Mustard, Davies and Foster are all in there however, and Mustard has been earning praise from all quarters for his outstanding keeping and explosive batting - he has been improving his longer innings in the CC and made two tons last year, and averaged highly in the FPT as he took apart most attacks thrown at him, earning praise from Warne. I'd push for him to be included but Ambrose would appear to have a strong case also.

Final comments for now: Edwards is impressing, and the wicket at Taunton can't be the only explanation, and Swann is doing well in a season not designed for spinners. Rashid's all-round capabilities keep him in there despite his struggles with the ball.