In terms of applications, you get InterVideo's WinDVD and a trial version of McAfee's Security Suite 2008, as well as several custom HP apps. HP Backup and Recovery is fairly self-explanatory, and offers scheduled backups in addition to custom HP Recovery partitions. HP ProtectTools Security Manager gives you central access to a large range of incredibly useful features for an office PC, such as device access management, smart card security and all kinds of privacy options including drive encryption.
This software security is further enhanced by an integrated TPM 1.2 (Trusted Platform Module) Embedded Security Chip. This hardware chip uses a silicon-embedded root key to enhance security through hardware encryption and authentication on TPM-enabled corporate networks. Aside from the common Kensington Lock Slot, there's also a hardware 'lock ring' for a padlock to prevent component theft.
Overall, while £680 might seem very steep for the hardware you're getting, you do get a well-built machine with a lot of extras. These include TPM and decent security management software and a three-year limited warranty backed by the biggest player in the PC industry. It's just a shame that the decision to go exclusively with DisplayPort, as opposed to DVI, means you'll have to rely on VGA for legacy components.
HP has produced a well made and flexible office desktop that offers good performance and security options, including a Trusted Platform Module. This makes it a worthy contender for your cash, though the lack of DVI in favour of DisplayPort is a factor that must be considered carefully. If you're already migrating to DisplayPort, or are happy to use VGA, then it's less of a problem, but if you're still wedded to DVI then this might not be for you.