A rule-of-thumb in American political science is that it takes roughly three years for a more clear indication as to what an administration's effect on the economy is. However, some effects may be felt earlier on, and I think that the anticipation over tax cuts is having a positive effect on the DOW and on some business expansion at this time. Whether that will be sustained over the long haul is another matter, and only time will tell for sure and that could be years down the road.
If the proposed budget is passed (either the House of the Senate version or a combination-- the latter being far more likely), I think it'll likely give the economy a bit of a boost, but there are some rather serious danger signs of what the prognosis could be further down the line because of lower and lower-middle taxes going up plus the effect of uncontrolled medical inflation that can really put a big-time damper on our economic future, especially since the projection is for a $1.4 trillion deficit over 10 years matched with shrinking middle-class incomes that are likely to continue. [howdya like that for one helluva run-on sentence]
BTW, a survey of economists from the Chicago School of economics, which is quite conservative, find that only 3% of them feel that the current proposals will be helpful in the long haul.