There's a good piece in last week's Taxation on the non-dom policies of both major political parties. The proposed charge on non-doms is a bit of a fudge, designed not to scare the donors horses. Mike Truman summons up the requisite and appropriate outrage:

there is no legitimate argument to be made for a policy which says that non-doms should be allowed to bung the taxman thirty grand in order to make him go away. It is a squalid, disreputable, grubby idea that has no place in the tax system of a major enterprise-driven, wealth-creating country.