I think we should stress that things are not all doom and gloom and that a Tory majority of 12 does not mean they will be able to do anything they want. We should celebrate our successes locally in Newham (thumping big majorities for both MP's) and in Ilford North.
We should all plan to argue, campaign and resist whenever possible and practical. We will win on some things and for those things we will lose, we must be able to lay the blame squarely on the Tories.
We must also point out that next year London must lead the way for an alternative set of economic and political values by electing a progressive Labour Mayor and Assembly. This must be our priority.
On a wider point I also think that Labour needs to win the battle of ideas with the public on centre left politics. It is no use saying we will make the NHS better or build more housing without asking those who can afford it for more money in taxes. People know this and unless they know where the money is coming from then you run the risk of someone claiming this doesn't really add up.