Improvements to the detail tool are definitely essential. I assume that they are already underway. Whenever a major new feature like this is added it always starts out somewhat limited and is then improved in subsequent releases. The Section tool has improved dramatically since its introduction (yes, it may seem hard to believe, but there was a time when there was no section tool and sections and elevations were separate 2D lines files generated from the 3D window) and I am sure we will see the same for details.
I think this is a good thing on two levels. One is that we have the detail tool sooner than if we had to wait for Graphisoft to implement all the features they can think of. Second is that the improvements are informed by our feedback, especially now that we have this excellent forum.
I will attempt to summarize the desired features to facilitate further discussion:
1. Place detail markers in other details. This could be limited to detail references only, as far as I am concerned, if the complexity of nested source views is too much to sort out. This one is very important (IMHO - and should be pretty simple, for references anyway) to make the tool fully useful. It should also be combined with the ability to place section markers as references in plans, sections and details. This way all drawings could be fully and completely cross referenced by the one convenient and automatic method. As it is now I have to continue to use library parts in sections and details to place references to other sections and details. Since the markers look the same (or similar) I have to differentiate them by text color so people can know what they are looking at.
2. Model/Drawing view option like the Section windows. I am not sure how useful this would be to me. It would be desirable in working on enlarged plans but adjusting the model in section details seems dangerous. This wish could also conflict with the other wish to show 2D data like text, dimensions and 2D library parts. How do you define the relationship between the live 3D elements and the 2D ones viewed from the other drawing?
3. Keeping the relative origin. Details should retain the same relative origin when they are derived from a source view. This seems very important and not hard to do. It could also relieve some (or all) of the desire for showing 2D elements from the source by making copy/paste much easier.
4. Displaying 2D elements from the source view. I think this one is rife with troubles. Besides the obvious conflicts with the desire for live model views, there are the issues of having multiple levels of annotation. The potential for confusion is considerable. I can imagine users asking: Are the section and detail markers drawn in the floor plan or added in the enlarged plan? Is this note in the building section or the section detail? If I move this dimension how does it affect the other drawing?
I have to say that I am fundamentally opposed to this one. It is contrary to my vision of the Virtual Building ideal of "model the building and annotate the views". Annotations should be specific to the view/drawing that they annotate and not cross the line into becoming a part of the building (unless, of course, you are putting a compass rose into the paving, or going retro with some sixties style super-graphics

). The addition of this feature is also in direct conflict with my vision for the future of ArchiCAD as expressed in
New Working Environment. Trying to keep track of where annotations originate seems like a big hassle compared to the occasional copy/paste for common notes.
5. Zone stamp display in details (and section). This is very different from the annotation issue above. Zones are very much a part of the building and as such should display appropriately in all views (this is, of course, another, related wish which has been discussed before). The zone should incorporate an internal list of all the views in which it is visible and allow moving and resetting the the zone stamp in each view. There should also be a way to define which zone stamp should appear in each type of view. While this could be handled in the GDL script of the stamp, it would be much better to set it up in the Zone Categories dialog by allowing different stamps to be assigned to plans, sections and details.
That's all I can think of for now. If you have some more to add please number them starting at 6. so we can keep track of them. I think this is a hugely important topic and would be well served by some orderly numbering of the items.