The HD is still upgrade-able.
Even thought, they said at the GamesCom-Conference that the Slim would have the same features, I read on several places that they would remove support for Linux (but afaik only for the new Slim-Model).
Full Hardware-Acces would still be cool.
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux