Good for them, actually. Yes, there's a lot of hard feelings, but this is what they should have been doing from the beginning.
Sue the people distributing MP3's illegally en mass for a profit, NOT the individuals.
That said; AllofMP3 charged $10 for unlimited access. The RIAA would make $1 per song download.
How the heck does the RIAA think they can sue for $150,000 per song? The most you can imagine in damages would be $1 per song.