Last December, he poleaxed the pensions industry by abolishing plans to allow art, fine wine and residential property into self-invested personal pensions.
Fireworks in previous years include the 10p starting tax rate and minimum income guarantees for pensioners.
The pre-Budget report, out on Wednesday, has a history of surprises, and Gordon Brown's PBR 2006 might not be any different. Intended as an opportunity for the Chancellor to update economic forecasts, it was billed as a taster to the Real Thing in the spring. But it has since morphed into a neat piece of theatre that sends members of the financial services industry scurrying to pore over its fine print.
This week, magnifying glasses will be out for a couple of anticipated announcements. Most likely is a change of tack on the "alternatively secured pension" (ASP). This new rule seemed to mean you no longer had to buy an annuity - the income for life from an insurer swapped in exchange for your pension pot - by age 75. Instead, while drawing a small income, you could keep your pension pot invested in the stock market or other assets until you died and - crucially - pass on a great (taxed) chunk to heirs.
However, it soon transpired that this "rule" was to be restricted to a tiny Christian sect objecting on religious grounds to actuaries (rather than God) working out your date of death. And after a groundswell of criticism at such a discriminatory benefit, Mr Brown is expected to abolish it, or to make fundamental changes.
Many in the industry also expect further loosening of the individual savings account rules, with further details of trailed proposals to allow you to switch money saved in an equity ISA fund into a mini cash equivalent without trashing your annual £7,000 allowance.
Motorists with gas-guzzlers are likely to be hit with higher vehicle duty, and a number of accountants and brokers believe the Chancellor will also introduce new measures to prevent people avoiding inheritance tax.
This likely last PBR as Chancellor is probably his first as prime minister in waiting: it's unlikely he'll do anything too unpopular.
Saint or sinner?
Nationwide's decision to drop its "same rates for all customers" (see News, page 21) jarred horribly with TV ads about greedy rivals offering top rates for "brand new customers only". The building society cites commercial pressures and industry trends away from "one-size-fits-all" rates to individual pricing.
Rivals have been indulging in gleeful Schadenfreude but it's worth remembering that the mutual remains - for now at least - a force for good.
Its cheap overseas card use and ATM withdrawal fees, and campaign for fee-free ATMs in the UK stand unvarnished.Reuse content