If it is in fact true that the RIAA is advancing a 'new' argument that the mere act of copying to a computer is illegal, it will be very interesting to see how this plays out. If they thought they were losing in the court of public opinion before, this should be an eye-opener.
IMHO the RIAA in some sense deserves some of what they're getting due to their continual attempts to play both sides of the basic issue - is a recording a physical 'thing', or is it merely a container for licensed content. These lawsuits are all based on the idea that the 'important part' is the licensed content. However, when it suits their purposes, the RIAA treats recordings as physical things as it greatly increases their profit margins. By obscuring this distinction in their own actions, they are at least partially responsible for the end user confusing the two, at least in my opinion.
IMHO if the RIAA had been more formal in establishing a pricing model that explicitly differentiated between the 'license cost' for the content and a 'media charge' for the physical CD, then they would have better standing for their lawsuits. However, this would almost certainly mean that they would have to offer media replacement services, and possibly even media upgrade services (i.e. trade in the vinyl copy for the CD, and only pay the new media charge). Avoiding both of these things - particularly the winfall of getting everyone to re-purchace their vinyl/casette collections on CD - have been big money-makers for the RIAA. It's somewhat surprising to me that they can get away with claiming that the licensed content is the true value in the product and they deserve to be compensated for sharing based on this, but then turn around and insist that my license to that content is null and void if the CD gets scratched and won't play on my system, forcing me to shell out the full cost of both the media and the license to replace it.
In contrast, the software industry gets this right. When you buy software these days, you pay $X for the right to use the software. If you also want physical media/manuals, there is an additional charge which is basically just a nominal markup on the production cost of the physical goods. If I then want to get replacement media for some reason, I simply pay the media charge again, not the full license cost of the software. (Of course, there are maintenance charges and upgrade fees etc that the software world has access to that the RIAA doesn't, but I don't think that undermines the basic point)
I do fully agree that some degree of prosecution is needed against those that are deliberately and knowingly violating copyright by blatant and large-scale downloading. IMHO there isn't any ambiguity in the idea that downloading music that you've never paid for in any form is illegal, and you should be open to prosecution for that. However, the RIAA is perversely going after the folks that are doing the sharing rather than the folks that are downloading; since by definition they have paid for a license to the content, this means that the the issue is inherently more ambiguous. Certainly, it is more cost effective as they can nail a single sharer for 1000's of copies of each song, but IMHO it seems to obscure the issue - the greater guilt should be associated with the person that actually does the stealing (i.e. downloading), not the enabler - shouldn't it?
Anyway, it isn't (at the moment) stopping me from continuing to move all my legally purchased CD's onto my file server, as computer-based playback is my primary source (and soon it may be my only source).