pension tax relief to be reduced?

If you are able to, financially and annual allowance wise, and you have paid sufficient tax to make use of the tax relief, and you want to put more into a pension, then you definitely should do it as soon as. IN which case also remember that you can take advantage of previous years unused allowances (carry forward, 3 years) though please check whether the change from 50k to 40k allowance still allows you to make use of unused prior years where prior year contributions were over 40 but less than 50: I believe they do but worth checking. but also make sure you understand any impact that might arise from the Lifetime Allowance as well. 

Don't get me on the subject of pension contribution rules. If you want to encourage people to save for a pension over decades, the insanity of constaintly re-jigging the rules and thereby making it impossible to reliably do long term finanicial planning makes me incandescent.

EDit: and on the wider points. yes you will still need to pay tax on pension income later. And if you exceed the LTA - which by definition is virtually impossible to plan for as its based on value at point of benefit crystallisation - you will pay a penal rate of tax (50), and that is current rules. And yes, the isa changes were widely viewed as starting to be a move away from pension contribution relief, and yes there was also quite a lot of discussion - if I recall correctly - about the concept of 'pension isas'. An important point about salary sacrifice is that currently it also provides a nic's benefit. Since that in turn has an employer benefit (employer nics is also reduced) I'm sure that company tax accountants will be thinking very hard about how they concoct a way to make a salary sacrifice scheme work regardless of income tax relief being at some fixed rate rather than marginal rate as now.