During their interview with Brad Childress, the Vikings knew immediately that he was their man. They were so determined that they talked him out of leaving town to meet with the Packers and immediately started talking money with Childress' agent. The Vikings knew that if Childress left town, there may well be other offers waiting for him and at the minimum, they may get engaged in a bidding war and at worst, could lose him to another team. Their determination worked.
The Eagles sort of planned on losing Childress this off-season, since he was already a hot commodity a day after the season ended. No less than four teams had Childress at, or near, the top of their list to fill coaching vacancies. Green Bay was especially interesting since Childress had served as an offensive coordinator at the University of Wisconsin, helping to lead the school to five bowl games, before he joined Andy Reid's staff in Philadelphia. Not only did Childress cancel a meeting with Green Bay, but at about the time that he'll be introduced as Vikings coach, he was supposed to be meeting with members of the Houston Texans to talk about their head coaching job. Last off-season, Childress interviewed with the Cleveland Browns, but that job ultimately went to Romeo Cornell and Childress returned to the Eagles. Few people around the NFL are surprised that Childress was getting as much consideration as he did. The only potential down side to Childress getting a head coaching job was that he wasn't calling the plays for the Eagles offense, since Andy Reid handled those duties. Reid himself defended Childress though, saying that he didn't call the plays when he was on the Packers' coaching staff.
As for whether or not Childress will try to take anyone else from the Eagles' staff with him, it's too early to tell. Childress has reportedly talked with members of the Vikings' coaching staff, but hasn't publicly disclosed whether he'll make any changes to the staff. It's not likely that the Eagles would be very willing to allow any members of their staff to leave to join Childress. To fill the vacancy, the Eagles are likely to promote assistant coach Marty Mornhinweg to offensive coordinator. Childress was signed through 2008 with the Eagles, but they gave permission to the Vikings and other clubs to talk to Childress for their coaching vacancies. While it's not clear how long of a contract Childress will get, it figures that the Vikings will add at least one year and a good amount of cash to the deal that Childress had in Philadelphia.