The thread on the store support forum says that an effort will be made to try to retain unique items that would not normally have a long shelf life.

There is still a sentiment that older characters have run their course. That's a shame because there are a lot of great older products, that were created for V1/2 and M1/2, that are no longer available. I still use those figures because I have a ton of content for them and they still look good. I'm not going to spend as much for V2 clothing as for a V4 clothing, but will buy it if the price is right. I bought a few last year and will buy more this year if the opportunity presents itself.

Maybe somebody will someday open up a storefront for these older items at a discount price.

My visual indexes of Poser content are at http://www.sharecg.com/pf/rgagnon