What can Wales expect in tomorrow's Budget?

After a while, Budgets tend to blur into one.

Was the "omnishambles" last year? Or was that the year that the Lib Dems leaked the contents and tried to claim the credit? Or was that the year that a newspaper tweeted its front page and had to apologise for breaking an embargo on publication?

Possibly, all three. I'm paid to ask the question: "What's in it for Wales?" This was the answer offered by the Wales Office last year - where would we be without those Barnett consequentials? The Wales Office figure of £161m more for capital spending sounded large but was a) spread over two years and b) reduced by cuts in revenue spending. So a reminder for this year: don't get too excited about changes in annual budgets that amount to a fraction of one per cent.

The challenge for us is to find out what George Osborne's Budget for a "resilient economy" means for people as well as for institutions, for the parent with large childcare bills as well as the politician. The Liberal Democrats say 83,600 families in Wales will be eligible for help with childcare costs announced today. Tory MP Alun Cairns puts the figure at 140,000 families. Both halves of the coalition can't be right.

Now, what else? The chancellor won easy headlines by freezing fuel duty for motorists - he's already said he's minded to do the same again. The Budget is one of those increasingly rare political events that affects people across the UK in similar ways.

Income tax, for now, remains reserved to Westminster. The increase in the personal tax allowance announced last year - which takes effect next month - would, said the Wales Office, benefit 1.1m taxpayers (i.e. most of them) and lift 12,000 low-paid people out of income tax altogether (although people earning £8,000 still pay national insurance). Expect a similar headline tomorrow as the allowance is expected to be raised again.

You may have noticed a bit of a debate about the impact of below-inflation increases in the threshold above which taxpayers pay the 40% rate. There are more and more of them, although only around 15 per cent of taxpayers pay it across the UK. Figures unearthed by the Silk commission show that in 2010 just seven per cent of taxpayers in Wales - 89,000 people - paid the 40 per cent rate. They were responsible for one third of all income tax revenues in Wales.

George Osborne has effectively ruled out helping what today's Daily Mail described as the "victims" of the 40 per cent rate, preferring to focus on the lower-paid. It may not win him favourable headlines in the Mail but raising the personal allowance will clearly have more impact on more people. Some Tory MPs, it should be said, are uneasy about taking people out of income tax altogether as they fear those who don't pay tax won't understand the need for public spending cuts or vote for parties making them.

The run-up to the pre-Budget report in December was dominated by calls for lower energy bills as the government tried to respond to Ed Miliband's conference pledge that a Labour government would freeze bills for 20 months.

A lot of the focus was on domestic bills, but large companies have eye-watering bills that have been linked to job losses. I understand the Wales Office Budget submission to the Treasury suggested the chancellor could find ways to help industry. All you need to know about the carbon price floor is here.

Expect an announcement about more money for flood defences in England and listen carefully to see whether it's new money and where it comes from. If it's new Treasury cash, Wales may get a share; if it comes from the Department for Communities and Local Government's pot expect UK ministers to remind everyone that flood defences are a devolved issue.

I mentioned the commission on devolution once, and I think I got away with it. But it wouldn't be a George Osborne Budget, pre-Budget report or spending review without some reference to Silk and the M4. The Treasury's national infrastructure plan published more than two years ago promised that the UK government would "engage with the Welsh government on improvements to the M4 in South East Wales".

Last year's Budget allowed the Wales Office to say: "The government is continuing to discuss options for funding improvements to the M4 in South Wales with the Welsh government, alongside an assessment of the Silk commission's recommendations, and will be reporting on progress in due course."

"In due course" may have come and gone, but - 10 years after plans were unveiled to ease congestion by building a relief road around Newport - the road is yet to be built - or paid for.

Little wonder then that Budgets do tend to blur into one. Come back here tomorrow or follow @davidcornock on Twitter to find out more about what the 2014 Budget means for Wales.