I have been using HPNA2.0 ever since there were more than 1 computer at home, and I still use it. Buying new HPNA PCI cards were nearly impossible, and I didn't want to shell out hundreds of dollars to move to Powerline. Luckily I found it on eBay for something like $2 (plus reasonable shipping), so I got 4 more (1 for backup). HPNA is the only reason I haven't started using Linux (there simply isn't much support, if at all, and definitely no "out-of-the-box" support). Nobody supports HPNA anymore.
If anyone know how to fix the Linux/HPNA problem (both USB and PCI), please respond.