Since the middle of the 19th Century, Uruguayan politics has been dominated by two major parties: the Colorados (Reds) and Blancos (Whites), which can be characterized more or less like the Democrats and Republicans, respectively. Today, however, a new chapter in history has opened in Uruguay as the Left Wing Coalition, the Frente Amplio, has won the election with 52%, making Tabare Vazquez the new president-elect of Uruguay.
The key here is that he won enough of the vote to avoid a runoff which would have put the Leftist victory in doubt.
Either way, this is definitely a huge win for liberals everywhere, as Uruguay rejects the current president who has sucked up to the United States throughout his term. Kirchner in Argentina, Lula in Brazil, and Lagos in Chile have another Social Democrat to help move South America forward.
Tabare is expected to lead Uruguay in the same fashion as Lula has in Brazil: somewhat moderately. He is a new hope to Uruguayans tired of the corruption that marked past governments led by the major parties.
For more info on Uruguay and this election, here's a great NY Times Article