Well I thought I'd have a look at this one since I liked the first Juiced. Now that I have a 360, and my old trusty PS2 I thought I'd try both and see the differences.
Here is the blurb on it
Juiced 2: Hot Import Nights evolves the current street racing scene, letting players experience the culture of the real-life HIN tour, the nation's largest lifestyle custom car show in an intense racing experience. Featuring track and drift racing at real-world locations around the globe, next-gen AI and unparalleled vehicle customization, Juiced 2: Hot Import Nights brings street racing to life, allowing players to test their skills at live street racing events against a back-drop of DJs, models and musicians. Groundbreaking new features include addictive drift/powersliding races and "Driver DNA" that tracks gamers' personal driving traits. These profiles, along with the profiles of select celebrities will be available for download across all online gaming systems. Racing developer Juice Games has evolved the game-play that revolutionized online racing, giving players the power to create their car, assemble their crew and put it all on the line in intense pink slip and crew races. Gamers will also be able to bet cash on each event, bringing a gambling element to the game that greatly increases the importance of each race.

Xbox 360 Special Features

Real-Life HIN Racing Experience - Juiced 2: Hot Import Nights combines an intense, addictive racing experience with the culture of the real-life HIN tour, the nation's largest lifestyle custom car show. Drift / Powersliding Races - Perfect your skills in multi-car drifting races. Driver DNA - Tracks each individual player's driving habits, creating a profile that can be downloaded off all online gaming services. Celebrity Driver DNA - Download celebrity DNA and test your star power skills. In-game Gambling - Watch and bet on live races with up to 1000 others. Unmatched Customization - Be who you want to be - With 90 digitally scanned cars and over 250 aftermarket mods and numerous combinations of character features, players can treat themselves to the ultimate car and driver customization. Online Pink Slip and Crew Racing - Tap into your inner risk-taker by challenging other players for their cars and putting yours on the line. Dominate the rest of the competition by racing online with friends you hand-pick for your crew.

PS2 Special Features

Real-Life HIN Racing Experience - Juiced 2: Hot Import Nights combines an intense, addictive racing experience with the culture of the real-life HIN tour, the nation's largest lifestyle custom car show. Drift / Powersliding Races - Perfect your skills in multi-car drifting races. Driver DNA - Tracks each individual player's driving habits, creating a profile that can be downloaded off all online gaming services. Celebrity Driver DNA - Download celebrity DNA and test your star power skills. In-game Gambling - Watch and bet on live races with up to 1000 others. Unmatched Customization - Be who you want to be - With 90 digitally scanned cars and over 250 aftermarket mods and numerous combinations of character features, players can treat themselves to the ultimate car and driver customization. Online Pink Slip and Crew Racing - Tap into your inner risk-taker by challenging other players for their cars and putting yours on the line. Dominate the rest of the competition by racing online with friends you hand-pick for your crew.

As can be seen the features are similar for both, reading the reviews on Gamespot, the PS2 release lacks alot of online play whereas the 360 version has quite a bit. You can also see the vast superiority of the 360 version graphically (but since this was also released on PS3 im sure Sony wont worry too much about it).

I haven't played the PS2 version as yet, but I have played the 360 version, and I have to say, in the interim until the new NFS comes out, Juiced 2 fills a nice void. It has a Unique training mode (Driver DNA) where you upgrade your character throughout the game. I have completed the rookie races and group 7 races, and let me say the game does get hard fast. This game has also been released on PS3 (as stated above), PC, PSP and the DS so lots of cross platforming here