Hi,
Here is a thought, I think which is not a lot of work and would be really great for JReviews.
With Joomla 2.5, Joomla finally gets to use the "images" field of #__content with a JSON information :
{"image_intro":"path-to-image","float_intro":"","image_intro_alt":"","image_intro_caption":"","image_fulltext":"path-to-image","float_fulltext":"","image_fulltext_alt":"","image_fulltext_caption":""}
I know JR 2.4 is way more flexible. However, there are a lot of great modules which can't be used with it (like RokSPRocket) and I think it would be quite complex to make them do (I tried with this module, and I've been stuck at one time…).
However, I think it would be quite easy to add a step in the
setMainMedia() function (or another one if I'm mistaken) :
Each time a MainMedia is set, the function could set the JSON record for Image Intro. Of course, it's duplicate information. But
it could ensure a total compatibility to any com_content compliant module !!

(Of course, we won't have fields support for RokSPRocket but that should be a work from RT Team that, souldn't it ?

)
Kristian, Alejandro, what do you think ?
I know you're in the middle of debugging but I think of all the people (like me) who will use JR2.4 to migrate to J2.5 ! You could save a lot of headaches I think.