I am the author of the customfields plugin. Recently many people have been asking when customfields will be available for GLPI 0.78. I apologize that I have not had a chance to reply to everyone yet. I decided it would be better to post a message here for everyone.
Up to this time, the development of the customfields plugin has been almost entirely funded by Oregon State Data Center. The bad news is that they do not currently have any need for an upgraded version. However they are willing to contribute 10 hours of time towards an upgrade. The plugin is quite complex and uses several workarounds to overcome limits of the plugin system, so my current estimate is that it will take about 100 hours to upgrade. If several companies can pledge to fund 10 or 20 hours of development time to accomplish the upgrade, then I will begin work on it. If you are able support this plugin, please send me an email (ryan at uniquesights dot com) to let me know how many hours your organization could fund (at $50/hour), and I'll get back with you to balance the actual development cost between sponsors.
Now for the good news. I have discovered how to integrate custom fields into standard forms. So a soon-coming 0.72.x release will allow users with a little PHP knowledge to put custom fields on to their main forms (and these fields work with new items as well as existing items). I have an idea to extend this further to make it possible to rearrange most forms (mixing standard and custom fields) with a simple management screen inside GLPI. This will probably take another 30 hours of work beyond the upgrade above, so it will probably be phase 2.
I hope this helps clarify the future of custom fields--as an open source project we really need help from the community to move it forward.