UPDATE: They've decided to call the jump off because of gusty winds. The winds caused a five hour delay this morning from the original starting time. The winds died down eventually and they thought they had a window, but problems with the capsule's communications systems delayed getting everything set. They had the balloon almost filled when the winds picked back up and it became clear it was too dangerous to take off.
They might try again tomorrow, but there's no guarantee the winds will be calm enough. The forecast says the wind will be higher than today, according to Weather Underground. Thursday seems like the most likely day the jump could occur.
Original: Daredevil parachutist Felix Baumgartner will attempt to break the record for the highest sky dive ever today and his death-defying free fall will be broadcast live on YouTube. If successful, Baumgartner will step out of a custom-made, 55-story hot air balloon more than 120,000 feet above the Earth, fall more than 100,000 feet (about 22 miles) in five-and-a-half minutes, reach a top speed of 690 miles-per-hour, and become the first human to break the sound barrier without the help of a jet airplane.