Taper Relief
How did Darling (ie. Gordon) manage to get rid of the only thing that makes CGT make sense - taper relief?
Taper relief rewards longer-term investment, and discourages fee-generating 'churn'. All taxes distort behaviour, but at least taper relief does it in the most constructive way for long-term business/investment planning.
Instead - by removing taper relief - Darling-Brown has sent a curious message: on one hand, people who have made a killing through buy-to-let capital growth are going to be given an extra 30% of these hardly productive gains when they sell (ooh - what do you think that will do for affordable housing, eh?).
On the other hand, there is now far less reason to build businesses for the future - or indeed, to make any long-term business/investment plans, since we now have no way of predicting what this inconsistent government will do next.
There's a huge difference between simplifying the tax system - the complexity of which Gordon himself is mostly responsible for - and producing a simplistic tax system.
A more logical government would extend taper relief to more areas. For example, it's crazy to have incremental tax (stamp duty) on selling a house: the next seller will simply add the 'lost' cost onto the new price (again, fuelling house price inflation).
Far simpler to abolish tax exemption for the house you live in, and have Capital Gains Tax on the increased value of your house - but with taper relief to make it negligible after a few years. This would have a stabilising effect on the housing market, and damp excessive price movement.