When not busy spying on journalists, HP does pretty well for itself and the HD100 is the first USB 2.0-based external HD-DVD player. If you want to take advantage of the drive's HD-DVD playback, you'll need at least a single-core 3.2GHz Pentium or an AMD 64 X2 2.2GHz. (And companies wonder why consumers aren't jumping on the high definition DVD bandwagon yet.) Furthermore, if you want external output, you'd better have an HDMI or HDCP-compliant DVI-D cable lying around. Otherwise, you're in for quite a disappointment. It also won't burn regular DVDs. Quality.
It's due by the end of the year, with an unknown price right now. I'm sure it'll be reasonable.
HP HD100 [Everything USB]
Press Release (PDF alert!) [HP]