All we can do is hope.
I am sure the media and general public will give him all the credit as well as the blame (abiet softened becuase of his party affiliation) for everything that occurs under his adminsitration just as they have for all his predecessors.
Clinton took credit for the upswing in the economy that was started before he was in office too, though as I understand it outside of minor stock fluctuations cuased by having the tresury department F with the value of the dollar; the market truely turns on much more long term instigations instituted from a variety of sources often beyound the direct power of any president.
Unfortunately most of the economic proposals I have heard Obama make have been all too simular to those introduced by FDR, which as history shows had little if any benifical effect for getting us out of the great drepression compared to our involvment in WW2. (which would not work today due to the way the military industrial support system functions)