Premise:
"And guess what, on Monday, I saw in the driveway of his house?"
Hypothesis: Don't try guessing what I saw on Monday, you have no chance of getting it right.

no

Premise:
"They think Gates is stepping down-contrary to Ballmer's insistence that Gates is stepping up to his new job-in hopes of appeasing Justice Department warriors who want Gates' head."
Hypothesis: The hope to pull the wool over the Justice Department's eyes.

yes

Premise:
"I had to format both drives."
Hypothesis: The intern messed with the drives.
it is not possible to tell