McCullum's still worth keeping for his wicket keeping alone, which is why his form dip isn't a worry for me. Plus he's in the lower order. It's not his fault he keeps coming in when we're in trouble and the other side has their tails up.
Vettori still seems to preform with the bat though. McCullum's just not that good with the bat period. It's all well and good to smack a quick 50-60 in a limited overs match but you actually need a defensive technique to survive in test cricket, McCullum's is horrible. He angles most of his defensive strokes towards the slips, or he'll push really hard outside off-stump when defending against the quicks.
Since the England tour in the middle of 2008 he seems to have no idea how to play an innings, it probably didn't help he was pushed up and down the order mind you. Best bet for now would be getting him to open and just play his strokes, Australia did it with Watson, Sri Lanka have tried it with Dilshan and maybe it would work with McCullum.
1.Martin Guptill
2.Brendon McCullum (WK)
3.Peter Fulton
4.Ross Taylor
5.Jesse Ryder
6.Neil Broom
7.Another middle order batsmen
8.Daniel Vettori
9.Shane Bond
10.Iain O'Brien
11.Chris Martin
Face it, we need the extra batsmen. I wouldn't know who else to include though, maybe give Flynn a spell down at 6-7. We have much better middle order batsmen going around at the moment and McCullum wouldn't do any worse then the ones that have been tried. Jesse Ryder to provide 5-10 overs a day as the 5th bowler also.