While in the world of hard drives the number one selling point is storage capacity, HP is going against the grain and is introducing another desktop with a small solid state disk. The DC7800 will come with a 16GB SSD as a stock option, making it an all-around energy efficient unit but a bit cramped on space. That won't bother their target market, HP thinks, with business desktops in environments that make heavy use of application servers or networked storage.
This is in addition to the thin clients they are also introducing, putting them in an interesting spot of selling "entry-level" hardware that doesn't glorify having the best of everything. The primary goal here is to appeal to the energy-conscious crowd, and with that being such a growing market it is probably a good move by HP. HP will be relying on Sandisk's drives for the machines, though the 16GB might be too much of a constraint for many. I expect to see 32GB or 64GB versions soon.