For those of you that have already posted and suggested there might be Custom Firmware 6.00 M33 on the way, will be slightly disappointed. As Alek, the admin of dark-alex.org has posted that CFW 6.00 M33 isn’t planned and not to ask for it.
Quoting Alek’s PSPWiki post:

Please, don’t ask here, the Blog, IRC, etc for [...]

Alek, the forum admin of dark-alex.org has set the record straight on their PSPWiki site. That Dark_AleX is not leaving us and quitting the PSP Scene. Also that the Dark-alex.org forums were closed due to costs. Not for other rumored reasons.
Quoting Alek’s post:
This really isn’t “Wiki News” but seeing as there is a traffic increase [...]

Sad to see, but the administrator Alek of the Dark-Alex.org forums has decided for the better. To close the forums, after a year of service to the PSP community. Its sad to see, I certainly hope Dark Alex hasn’t quit for good either, as some have rumoured he might have…I guess time will tell if [...]

Team Red Bull PSP have released a version of Dark_AleX’s Despertar del Cementerio. Their modified Despertar del Cementerio v8 Mod allows users to install complete Custom Firmware, like 5.50 GEN-A or 5.50 MHU. As well as install 4.01 M33 and emulate Custom Firmware 5.00 M33 using the memory stick. Warning this is only for PSP-1000 [...]

Dark_AleX has updated his Despertar del Cementerio tool to version 8.
This will now allow users to create MMS sticks that go directly to 5.00 M33-4, which appears to be the only change from DCv7.
Note that this will NOT work with PSP-3000 models and those with TA-088v3 motherboards, despite the new TOOL battery from Datel.
Download: HERE
Source: [...]