NU wanted to have a deal agreed to by Tuesday. Frost hadn't committed so on Wednesday NU started working on Fuente harder - and there was mutual interest there. However, it was agreed to give Frost until Saturday.
NU struck a tentative deal with Frost on Friday, though still working out some details - salary pool for assistants, etc. Frost has turned away all other suitors - Florida, Tennessee, etc.
Since it's only a tentative deal, he could technically still choose to remain at Central Florida but, barring a dramatic change-of-heart on Frost's part - everything is set to go.