The 1000HD, like the 1000H, has a hard drive instead of flash SSD. But unlike the 1000H, which is Atom-based, the 1000HD has a Celeron. As such, it has more hardware in common with the other Celeron models than with the Atom models. Wifi is supported by the madwifi modules (Atheros AR2425 802.11abg) and ethernet by atl2. It has bluetooth and the four extra silver hotkeys, like the 901 and 1000(H) models.
In future, the DFSG-free ath5k module in Linux 2.6.27 should work on this system as an alternative to madwifi, but the new kernel isn’t in Debian yet and the patches for the AR2425 haven’t been applied to 2.6.26.