I was as surprised as you were by the differential treatment and timing of these tax changes.
The cigarette tax increase came into effect immediately, because we didn't want people to rush to the convenience store to buy cheaper cigarettes. However, on capital gains, we don't mind giving two months' heads-up to those who could rearrange their taxable business or affairs to escape the higher capital gains rates. I don't know why; that's surprising, to say the least.
The impact is that, on the cigarette tax, it's fairly straightforward; it was difficult to escape the tax increase. However, for capital gains, it's very likely to lead to a phenomenon where people will sell some assets before June 25, so that their capital gains will all be taxed at 50% rather than at the higher two-thirds rate. We are likely to see an increase in capital gains taxation, or the taxes collected on capital gains, in the current fiscal year, and probably a lower amount, or a displacement of capital gains tax revenues, from future years to this year.