Bluedisk DID release a CFW4.25, and seems guys on crunch confirmed it's true.
Now the bad thing about it - requires some kind of CD-KEY and is DRM'd anally.
It will only work for one console, since they use your EID0 to make it.
The good thing - it's downgradeable to 3.55 easily. Now just to know the price.
Here's BlueDisk's site.