There was some cast turnover this year, both in terms of the main cast and guest stars. Paulo Costanzo (who was on the show Royal Pains as well as the 2000 cult comedy Road Trip, among other things) was the main addition to the main cast, coming in as Lyor Boone, an advisor to the President (and the staff). While Virginia Madsen did not reprise her role, Michael J. Fox joined the series for a multi-episode arc, as did 24 alum Kim Raver. The season ended on a pretty big cliffhanger and, of course, was promptly canceled by ABC, only to be picked up by Netflix for a final season.
The DVD set is a six-disc set. Despite Amazon's listing, there is a Region-1 Canadian DVD release that will work in US DVD players. There is also a Region-2 set that is available on Amazon UK, but others have said this listing is for a Region-1 set. I bought mine elsewhere, and it was the Region-1 Canadian version. The video transfer is okay, but definitely not a high-definition transfer. The only extra/bonus feature is a 10-minute interview with Paulo Constanzo about joining the cast. Otherwise, all you get are the episodes. No deleted scenes, commentary tracks, or behind-the-scenes material.
The show does have a bit of a different feel than season 1, which is not surprising considering season 1 was centered around unraveling a conspiracy. While the second season started out a bit slow, it definitely picked up as it went along. I cannot guarantee everyone who liked or loved season 1 will enjoy this season, but I definitely think it is worth a look and will probably be enjoyable for most if you do not bail on it early on.