The piece above supports what I believe, which is that the Conservative Party is still some way to the right of Mr Cameron, as Labour is somewhere to the left of Brown.
In some ways I think a Cameron win may be the lesser of various evils, as a Cameron defeat would likely move the Tories even further to the right without a relatively 'left'/'compassionate' leader.
The problem for Labour, and I think politics and democracy, is that we have Brown Vs Cameron in almost presidential style, instead of the party politics which do show a real divide between divergant ideological views. Labour needs to make the point that only the dressing has changed, let's not forget that.
I have no doubt that Cameron IS to the left of some/many in his party, but they are only really happy to put up with him when he's successful. The economic crisis means the Tories will implement big cuts in their time in government, which will appease the rest of the party, but it depends on how far each goes/wishes to go as to whether he can do what he has so far succeeded at, i.e. getting the party to be very quiet while Cameron takes all the spot light