After recent events in homebrew-land, there is now in fact a real downgrader available for v2.5 and v2.6 firmwares, so you can partially ignore the news article below. Of course, instead of paying for a downgrader, you can just download it for free (as intended by the authors) from one of the many PSP news sites that are covering the news - e.g. here. We can't recommend it personally, because we haven't tested it ourselves, but the reports seem to have been good so far.
In other news, people have been asking what the future is for eLoader, and the new kernel-mode exploit on v2.5 and v2.6. We've been looking at the exploit, and trying to convert it into something more usable.
Right now, our aim is to develop something that no longer needs the full eloader to run homebrew. The ideal would be to hack the kernel in memory, so that temporarily it will allow homebrew to be run directly from the PSP's XMB menu. In theory, now that we have kernel-mode access, this should be possible, but it could take some time. In the meantime, I'm sure that others are probably also working on similar ideas.
We're busy with our normal lives at the moment, so please don't ask when something will be ready. The additional pressure simply discourages us from working on the PSP projects.
Voilà en gros ça explique qu'il dévelloppe un nokxploit mais il prend son temps donc pas pour tout de suite.
Source: http://www.fanjita.org/