This is a bad... though almost certainly irrevocable decision, though the approval is couched in terms of providing yet another competitive option for Broadband Internet Access.
It's bad because the BPL technology is inherently flawed. Much like ADSL over telephone lines, BPL works by transmitting a low-frequency radio-frequency signal onto power lines. Those power lines were not designed to conduct such signals, and as a result there will likely be widespread "signal leakage" from the power lines. The resulting interference from the signal leakage renders most current types of "High Frequency" (HF) radio services, such as Amateur Radio, overseas shortwave broadcasts, emergency preparedness backup communications links, unusable.
The FCC claims have included protections for such situations in the BPL rules it proposes to adopt. Such rules will be all-but-unenforceable because if interference is claimed, the onus is on the BPL service provider to eliminate the interfering signal. That will prove very tough to do when 1) interference could come from anywhere within thousands of miles of transmission lines or even from within a bad connection within an individual home or business, 2) the interference could well be intermittent, and 3) the service provider claims to offer a competitive service to DSL, cable modem, wireless, and satellite and thus loathe to shut down its distribution network to resolve an interference complaint.
Make no mistake - BPL does work, but the Faustian bargain that the FCC made is the end of usefulness for "conventional" HF communications - analog modes such as SSB. Thus... HF is brought under the influence of "The Darwinian Effect of License-exempt Wireless" where the wireless technology you use has to continually evolve (become more robust) in order to continue to use the spectrum which is growing more heavily used. Such technology already exists - digital modulation modes which can overcome BPL interference, and will, by necessity, become the norm for HF communications if BPL is widely deployed in the US.
Steve Stroh