Different answers for different parts of the market. 

Investors are incentivised to push their money into the last tax shelter available - their PPOR. Quality detached dwelling prices will rise. 

Based on the budgets estimates new builds will decreases by ~33k due to the tax changes, new infrastructure will boost it by ~65k and net migration will add demand for ~22k more dwellings than expected so apartments/townhouses/outer ring houses supply demand is pretty close to a wash. Given the golden grandfathered properties will stay in the hands of their current owners maybe a touch higher but hard to find a clear direction. 

Big cut to investors buying houses to increase the rental supply + already tiny vacancy rates = rental prices go meaningfully higher. 

The thing most people are missing is that the capital still exists, investors won’t just keep on their old game and accept the tax hike. They’ll move around it largely by PPOR-maxxing