yep, you download the saved exploit file, put it into you SAVEDATA folder, and start the Gripshift game, and if you check the FW, it will say X.XX HEN (i think).
Its either that Sony pulled it, or that it was sold out. I remember when they found out about the Lumines exploit to install CFW for people with 3.50 and below. It was being sold for $60+ on ebay. I got lucky and found one at gamestop for $17. Took awhile for Sony to pull it though. I think there was a store selling Lumines for $15, they sold out like hot cakes.
For the GTA:LCS exploit, they patched the game and released it as an "Greatest Hits"