Trying to understand the "fiscal summit"

To begin with, the "fiscal" portion of the title of today's summit refers to federal government expeditures. To wit, the New York Times reports that, "[the] president said that the bank-rescue plan and the broader economic stimulus program are necessary not merely to jolt the economy but because the country has “long-term challenges — health care, energy, education and others — that we can no longer afford to ignore.”

Ezra Klein notes that despite the coverage, the important aspect of the summit was the decidedly non-sexy structural shift of the budget "moving to a 10-year budget window rather than the traditional 5-year window."

Why does this matter? Sen. Max Baucus, the Senate Finance Committee Chairman, alluded to a 10-year window because such a window would "ensure time for the initial investment to give way to the eventual savings, may prove very important as the debate grinds on."