Gamers disappointed with the PS3's backwards compatibility (or the lack thereof) might find interest in reading the latest issue of EGM. In the mag, an interview with SCEA senior marketing VP Peter Dille and director of PSN operations Eric Lempel hints that PS2 backwards compatibility isn't completely down and out.
When asked about the lack of bc support possibly crossing out chances of ever having downloadable PS2 games via the PSN, Lempel answered back with "there are possibilities through technology and software emulation to make that happen." Lempel refused to talk about any specific plans, but hasn't flat-out denied that it isn't something being worked on.
On another note, Peter Dille states that PS2 backwards compatibility is still important to Sony. He reconfirms what we already know, that the removal of PS2 backwards compatibility helped lower the overall price of the PS3. However, consider the fact that Sony has cut production costs for the PS3 by half, and then the reason not to have "expensive" emulated bc seems a little moot. If Sony does decide to support downloadable PS2 games playable through emulation, it's very very possible that the software emulation could also play that precious PS2 disc collection of yours.